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Re: [Losmandy_users] Re: Polar alignment shifts after meridian flip


May 3, 2001

 


----------------------------

#3908 May 3, 2001

Anyone:



1. What's a good book which goes into detail on doing various forms of

polar alignment?



2. Please explain the implications of meridian flip -- when it is

necessary, when to seek it, and when to avoid it.



3. Please explain the implications of choosing East or West of the meridian

for alignment and for viewing. The G-11 instructions say that the mount

should be weighted to the East, but says little else.



Mike



----------------------------

#3910 May 3, 2001

--- In Losmandy_users@y..., Michael Rudolph mrudolph@t...> wrote: > Anyone:

>

> 1. What's a good book which goes into detail on doing various forms

of > polar alignment?



dickinson & dyer backyard astronomer's guide

>

> 2. Please explain the implications of meridian flip -- when it is

> necessary, when to seek it, and when to avoid it.



You don't really have much choice! As you move the scope around you

will cross the meridian.

>

> 3. Please explain the implications of choosing East or West of the

meridian > for alignment and for viewing. The G-11 instructions say that the

mount > should be weighted to the East, but says little else.

>

Alignment and viewing are two different issues. Alignment relates to

the computer that runs your mount. Your computer needs to know which

side of the mount it's on in order to know how to increment or

decrement dec. put yor scope on E side facing W and W side facing E

and turn it towards N. You will see you are moving in opposite

directions (to the right in one case, to the left in the other). The

computer needs to know where it is when powered up. For the rest of

the night it should be fine.



For dscs, all of this revolves on whether there's a "plus" or "minus"

in front of the dec initialization. I don't know how Gemini is set

up.



Weighting of the mount is important (it should be balanced or you

willharm motors). BUT, having a slight offset out of balance (which

requires readjustment depending on what side 0of the mount you are on)

is not strictly necessary. When the mount is slightly out of balance

in the "heavy" direction the gears make very little noise. When the

scope is perfectly balanced you get a tick tick. See the thread "Hear

the tick tick bunny?" in the archives. The mount seems to track fine

while ticking (at least for visual) and I've ceased worrying about it.



Indeed, there's something comforting about having the massive mount

with glowing red lights ticking to keep you company at 2 a.m. > Mike



----------------------------

#7147 Dec 6, 2001

Hi Group,



I've gotten the hang of aligning the Gemini so far on one side (

optics pointing towards the eastern sky, OTA on the west side of

mount). I finally tried to go to the western part of the sky-

meridian flip but the scope pointed way off of the alignment star

Vega. My question is, "what's the best way to do a meridian flip"-

either slew to the other side, center Vega then go to additional

align or go to bright stars, schroll to Vega then enter go-to, center

the star and finally enter additional align? Any info would be

appreciated.

Thank You!

CHRIS



----------------------------

#7148 Dec 6, 2001

On 12/6/01 9:26 AM bingsca wrote:

> Hi Group,

>

> I've gotten the hang of aligning the Gemini so far on one side (

> optics pointing towards the eastern sky, OTA on the west side of

> mount). I finally tried to go to the western part of the sky-

> meridian flip but the scope pointed way off of the alignment star

> Vega. My question is, "what's the best way to do a meridian flip"-

> either slew to the other side, center Vega then go to additional

> align or go to bright stars, schroll to Vega then enter go-to, center

> the star and finally enter additional align? Any info would be

> appreciated.

> Thank You!

> CHRIS



Goto errors with a meridian flip usually are caused by the optical axis of

the scope not being orthogonal to the Dec axis of rotation. If you don't

want to go through the trouble of trying to shim the OTA so it is

orthogonal, the work-around is to realign whenever you do a meridian flip.



Regards,

Robin



Astro Accessories by Robin Casady

Stainless Steel Weights & Dovetail Saddles

www.CarmelCoast.com/Astro/sales.html



Casady & Greene, Inc.

www.casadyg.com



----------------------------

#7154 Dec 6, 2001

--- In Losmandy_users@y..., Robin Casady rcasady@c...> wrote: > On 12/6/01 9:26 AM bingsca wrote:

>

> > Hi Group,

> >

> > I've gotten the hang of aligning the Gemini so far on one side (

> > optics pointing towards the eastern sky, OTA on the west side of

> > mount). I finally tried to go to the western part of the sky-

> > meridian flip but the scope pointed way off of the alignment star

> > Vega. My question is, "what's the best way to do a meridian flip"-

> > either slew to the other side, center Vega then go to additional

> > align or go to bright stars, schroll to Vega then enter go-to,

center > > the star and finally enter additional align? Any info would be

> > appreciated.

> > Thank You!

> > CHRIS

>

> Goto errors with a meridian flip usually are caused by the optical

axis of > the scope not being orthogonal to the Dec axis of rotation. If you

don't > want to go through the trouble of trying to shim the OTA so it is

> orthogonal, the work-around is to realign whenever you do a

meridian flip. >

> Regards,

> Robin

>

> Astro Accessories by Robin Casady

> Stainless Steel Weights & Dovetail Saddles

> www.CarmelCoast.com/Astro/sales.html

>

> Casady & Greene, Inc.

> www.casadyg.com





Hi Robin,



I'm not exactly sure what you are explaining. My set up is the G11

with the Gemini and 2 scopes TV85 -C 9.25 mounted on the Losmandy

side by side saddle plate. Maybe there can be no meridian flip for

alignment with this type of set up.



Thanks, Chris







----------------------------

#7157 Dec 6, 2001

Hello Chris,

> I've gotten the hang of aligning the Gemini so far on one side (

> optics pointing towards the eastern sky, OTA on the west side of

> mount). I finally tried to go to the western part of the sky-

> meridian flip but the scope pointed way off of the alignment star

> Vega. My question is, "what's the best way to do a meridian flip"-

> either slew to the other side, center Vega then go to additional

> align or go to bright stars, schroll to Vega then enter go-to, center

> the star and finally enter additional align? Any info would be

> appreciated.





Do the Initial Alignment at the side of your choice. Select some

objects at the same side, GoTo, center them, Additional Align.

After 4..5 objects you should have a good pointing model.



Now select an object at the other side, GoTo (w/ meridian flip).

Due to axis backlash and mirror flop you will be off significantly.

Center the object, Additional Align. Now Gemini 1) knows about the

backlash/flop and will take them into account on subsequent pointings,

and 2) the selected object will be used as a reference point for

further Additional Alignments done at this "other" side of the

meridian.



Ren.



----------------------------

#7159 Dec 6, 2001

--- In Losmandy_users@y..., Rene Goerlich Rene@D...> wrote: > Hello Chris,

>

> > I've gotten the hang of aligning the Gemini so far on one side (

> > optics pointing towards the eastern sky, OTA on the west side of

> > mount). I finally tried to go to the western part of the sky-

> > meridian flip but the scope pointed way off of the alignment star

> > Vega. My question is, "what's the best way to do a meridian flip"-



> > either slew to the other side, center Vega then go to additional

> > align or go to bright stars, schroll to Vega then enter go-to,

center > > the star and finally enter additional align? Any info would be

> > appreciated.

>

>

> Do the Initial Alignment at the side of your choice. Select some

> objects at the same side, GoTo, center them, Additional Align.

> After 4..5 objects you should have a good pointing model.



Hi Rene,



I will try it again on the next clear night. Robin gave me some

advice but i am not sure what he was saying something about shiming

the OTA? My set up is 2 scopes set on the Losmandy side by side

saddle plate on a G11. Scopes are the TV85 and C 9.25, i use the

refractor for aligning because of mirror shift. I hope i don't have

to align on one side and then do a complete re-alignment when i want

to view the other side.

Thanks again,

Chris >

> Now select an object at the other side, GoTo (w/ meridian flip).

> Due to axis backlash and mirror flop you will be off significantly.

> Center the object, Additional Align. Now Gemini 1) knows about the

> backlash/flop and will take them into account on subsequent

pointings, > and 2) the selected object will be used as a reference point for

> further Additional Alignments done at this "other" side of the

> meridian.

>

> Ren.



----------------------------

#7162 Dec 6, 2001

On 12/6/01 12:07 PM bingsca wrote:

> --- In Losmandy_users@y..., Robin Casady rcasady@c...> wrote:

>> On 12/6/01 9:26 AM bingsca wrote:

>>

>>> Hi Group,

>>>

>>> I've gotten the hang of aligning the Gemini so far on one side (

>>> optics pointing towards the eastern sky, OTA on the west side of

>>> mount). I finally tried to go to the western part of the sky-

>>> meridian flip but the scope pointed way off of the alignment star

>>> Vega. My question is, "what's the best way to do a meridian flip"-

>>> either slew to the other side, center Vega then go to additional

>>> align or go to bright stars, schroll to Vega then enter go-to,

> center

>>> the star and finally enter additional align? Any info would be

>>> appreciated.

>>> Thank You!

>>> CHRIS

>>

>> Goto errors with a meridian flip usually are caused by the optical

> axis of

>> the scope not being orthogonal to the Dec axis of rotation. If you

> don't

>> want to go through the trouble of trying to shim the OTA so it is

>> orthogonal, the work-around is to realign whenever you do a

> meridian flip.

>>

>> Regards,

>> Robin

>>

>> Astro Accessories by Robin Casady

>> Stainless Steel Weights & Dovetail Saddles

>> www.CarmelCoast.com/Astro/sales.html

>>

>> Casady & Greene, Inc.

>> www.casadyg.com

>

>

> Hi Robin,

>

> I'm not exactly sure what you are explaining. My set up is the G11

> with the Gemini and 2 scopes TV85 -C 9.25 mounted on the Losmandy

> side by side saddle plate. Maybe there can be no meridian flip for

> alignment with this type of set up.

>

> Thanks, Chris



Optical axis: Imagine your refractor without a star diagonal, so the

eyepiece is looking straight through the scope. Center a star in the scope.

Now, imagine a line going through the center of the eyepiece to the star.

That is the optical axis of the scope.



Dec axis: the axis on which the Dec rotates



Orthogonal: at right angles to each other.



So, the TV85, that you use for alignment, should be exactly 90 degrees from

the Dec rotation. Otherwise there will be a pointing error when you do the

meridian flip. The only issue with having a side-by-side setup is that the

SCT needs to be pointing where the TV85 is pointing if you want to find

things in the SCT.



Regards,

Robin



Astro Accessories by Robin Casady

Stainless Steel Weights & Dovetail Saddles

www.CarmelCoast.com/Astro/sales.html



Casady & Greene, Inc.

www.casadyg.com







----------------------------

#7176 Dec 7, 2001

--- In Losmandy_users@y..., Robin Casady rcasady@c...> wrote: > On 12/6/01 12:07 PM bingsca wrote:

>

> > --- In Losmandy_users@y..., Robin Casady rcasady@c...> wrote:

> >> On 12/6/01 9:26 AM bingsca wrote:

> >>

> >>> Hi Group,

> >>>

> >>> I've gotten the hang of aligning the Gemini so far on one side (

> >>> optics pointing towards the eastern sky, OTA on the west side of

> >>> mount). I finally tried to go to the western part of the sky-

> >>> meridian flip but the scope pointed way off of the alignment

star > >>> Vega. My question is, "what's the best way to do a meridian

flip"- > >>> either slew to the other side, center Vega then go to additional

> >>> align or go to bright stars, schroll to Vega then enter go-to,

> > center

> >>> the star and finally enter additional align? Any info would be

> >>> appreciated.

> >>> Thank You!

> >>> CHRIS

> >>

> >> Goto errors with a meridian flip usually are caused by the

optical > > axis of

> >> the scope not being orthogonal to the Dec axis of rotation. If

you > > don't

> >> want to go through the trouble of trying to shim the OTA so it is

> >> orthogonal, the work-around is to realign whenever you do a

> > meridian flip.

> >>

> >> Regards,

> >> Robin

> >>

> >> Astro Accessories by Robin Casady

> >> Stainless Steel Weights & Dovetail Saddles

> >> www.CarmelCoast.com/Astro/sales.html

> >>

> >> Casady & Greene, Inc.

> >> www.casadyg.com

> >

> >

> > Hi Robin,

> >

> > I'm not exactly sure what you are explaining. My set up is the G11

> > with the Gemini and 2 scopes TV85 -C 9.25 mounted on the Losmandy

> > side by side saddle plate. Maybe there can be no meridian flip for

> > alignment with this type of set up.

> >

> > Thanks, Chris

>

> Optical axis: Imagine your refractor without a star diagonal, so the

> eyepiece is looking straight through the scope. Center a star in

the scope. > Now, imagine a line going through the center of the eyepiece to the

star. > That is the optical axis of the scope.

>

> Dec axis: the axis on which the Dec rotates

>

> Orthogonal: at right angles to each other.

>

> So, the TV85, that you use for alignment, should be exactly 90

degrees from > the Dec rotation. Otherwise there will be a pointing error when you

do the > meridian flip. The only issue with having a side-by-side setup is

that the > SCT needs to be pointing where the TV85 is pointing if you want to

find > things in the SCT.

>

> Regards,

> Robin

>

> Astro Accessories by Robin Casady

> Stainless Steel Weights & Dovetail Saddles

> www.CarmelCoast.com/Astro/sales.html

>

> Casady & Greene, Inc.

> www.casadyg.com



Hi Robin,



I now fully understand and last night i tried a meridian flip. I made

sure that the 90 degree diagonal was at right angles with the DEC

axis. After a meridian flip the scope went exactly to Vega- worked

flawlessly. I know the SCT has to be inline with the refactor. I use

this set up to compare different objects with different aperatures. I

also use the TV85 for wide field viewing and scanning the sky. I use

the C 9.25 for viewing fainter objects and the planets.



Thanks again Robin

Chris



----------------------------

#9213 Mar 20, 2002

Sorry to revisit this subject but I lost my book mark.Will somebody

please remind me of the correct procedure for ballancing and re

ballancing after meridian flip.Thanks. George. Sirius b



----------------------------

#9216 Mar 20, 2002

Always heavy to the East.



Irrespective of where the OTA is at.



What I mean is if the OTA is on the West side,

then your heavy towards the weights (which

are on the East side of the mount).



If the OTA is on the East side, then your

heavy towards the OTA (which I guess

obviously is on the East side).



I have a mark on my shaft for where my 11lb

weight (I have a 21lb and an 11 lb weight)

needs to be for each side and just move it

as necessary.



Of course this only works if your set-up

tends to be the same all the time (and

mine is).



In my case the 21lb weight is below the

11lb weight.



I set up and balance everything with the

OTA to the West (i.e. heavy towards the

weight side).



Then I move the OTA to the East and move

just the 11lb weight until things are

slighty imbalanced to the East. The 21lb

weight stays fixed always.



I then marked where the 11lb weight was at.



So, if OTA is to the West, just slide the

11lb weight down until it is touching the

21lb weight.



If OTA is to the East move the 11lb weight

up to the mark.



Is this what you were looking for.



Regards,



-----Original Message-----

From: gsben2000 [mailto:siriusb@...]

Sent: Wednesday, March 20, 2002 6:38 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Meridian flip





Sorry to revisit this subject but I lost my book mark.Will somebody

please remind me of the correct procedure for ballancing and re

ballancing after meridian flip.Thanks. George. Sirius b







To unsubscribe from this group, send an email to:

Losmandy_users-unsubscribe@egroups.com







Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/







----------------------------

#9221 Mar 20, 2002

Thanks,it's what I thought.Just wanted to be sure. George.



--- In Losmandy_users@y..., Lacey James-CJL023 james.lacey@m...>

wrote: > Always heavy to the East.

>

> Irrespective of where the OTA is at.

>

> What I mean is if the OTA is on the West side,

> then your heavy towards the weights (which

> are on the East side of the mount).

>

> If the OTA is on the East side, then your

> heavy towards the OTA (which I guess

> obviously is on the East side).

>

> I have a mark on my shaft for where my 11lb

> weight (I have a 21lb and an 11 lb weight)

> needs to be for each side and just move it

> as necessary.

>

> Of course this only works if your set-up

> tends to be the same all the time (and

> mine is).

>

> In my case the 21lb weight is below the

> 11lb weight.

>

> I set up and balance everything with the

> OTA to the West (i.e. heavy towards the

> weight side).

>

> Then I move the OTA to the East and move

> just the 11lb weight until things are

> slighty imbalanced to the East. The 21lb

> weight stays fixed always.

>

> I then marked where the 11lb weight was at.

>

> So, if OTA is to the West, just slide the

> 11lb weight down until it is touching the

> 21lb weight.

>

> If OTA is to the East move the 11lb weight

> up to the mark.

>

> Is this what you were looking for.

>

> Regards,

>

> -----Original Message-----

> From: gsben2000 [mailto:siriusb@b...]

> Sent: Wednesday, March 20, 2002 6:38 AM

> To: Losmandy_users@y...

> Subject: [Losmandy_users] Meridian flip

>

>

> Sorry to revisit this subject but I lost my book mark.Will somebody

> please remind me of the correct procedure for ballancing and re

> ballancing after meridian flip.Thanks. George. Sirius b

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@e...

>

>

>

> Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/



----------------------------

#14210 Feb 25 4:18 PM

Hello group, I've been a gemini titan owner for over 700 hours now

w>. I've been through the setup routines concerning lat/lon; setting

utc, then in the evening running the polar assist routine (I cannot

see polaris in my backyard). Once I setup the telescope it points

great, very great. The images are rock steady. However, it will not

do a meridan flip. I'm really puzzled by this, please what have I

forgotten! I work mostly in the east south quad but objects in the

west more than 2 hours over the overhead RA, it will not flip. I have

not yet "told" the scope the "local" time (it "knows" utc), nor have I

set any safety limits. Is this the cause? - thank you in advance - Rod



ps - to Dave, heard anything yet?



----------------------------

#14211 Feb 26 5:12 AM

Rod,

> However, it will not do a meridan flip.



My understanding is that while tracking the Gemini WILL NOT do a

meridian flip. It will continue to track the object until a safety

limit is hit.



It might do a meridian flip if you told it to GOTO the same object

again after it has crossed your meridian, but I don't know this for

certain. I have never tried it.



This whole meridian flip concept seems to be a continual source of

confusion. I don't think it is as complex as people seem to think.



A meridian flip is just the act of moving the OTA to the other side

of the mount so that you can continue to track it after it has

crossed the meridian. Of course you would not want to do this in the

middle of a long exposure, so this is why the Gemini just continues

to track the object until it hits a safety limit.

> I have not yet "told" the scope the "local" time (it "knows" utc),

> nor have I set any safety limits.



I don't think you can tell the Gemini the "local" time. You tell it

utc and your time zone, and it figures out local time from that.



The Gemini comes with default settings for safety limits that are

conservative. So, you don't have to ever set safety limits if you do

not want to.

> ps - to Dave, heard anything yet?



ps - Dave not here :)



Regards,



----------------------------

#14212 Feb 26 9:30 AM

Hi Rod,

Dave here...



James Lacey gave you a good answer on the meridian flip. It won't

flip while tracking, but will flip when it is near the safety limit

and you do a GOTO. However, at least with the default safety

limits, the western safety limit is pretty far past the meridian.

It often surprises me how often a GOTO sends me past the meridian

without a flip. Rene's algorithm is that for targets that can be

reached with the OTA on either side of the meridian, he will only

flip if the object is within 10 minutes if hitting the safety

limit. If you really want to do a GOTO for such an object (more

than 10 minutes away from the western limit), manually slew the

scope to the other side of the meridian, then do the GOTO.



As for the RS-232 problem, Scott agreed to take a look at my

controller box. I sent it to him, and UPS told me that he recieved

it on 2/17. I haven't heard from him since, so I don't know what

he's found. I've emailed him a couple times since then for an

update, but he hasn't responded. So, I STILL don't know what's

going on and don't have my controller back. I'll let you know when

I finally hear from him.



Dave Sandage



--- In Losmandy_users@yahoogroups.com, "rod_bertelsen

rbertelsen@e...>" rbertelsen@e...> wrote: > Hello group, I've been a gemini titan owner for over 700 hours now

> w>. I've been through the setup routines concerning lat/lon;

setting > utc, then in the evening running the polar assist routine (I cannot

> see polaris in my backyard). Once I setup the telescope it points

> great, very great. The images are rock steady. However, it will

not > do a meridan flip. I'm really puzzled by this, please what have I

> forgotten! I work mostly in the east south quad but objects in the

> west more than 2 hours over the overhead RA, it will not flip. I

have > not yet "told" the scope the "local" time (it "knows" utc), nor

have I > set any safety limits. Is this the cause? - thank you in advance -

Rod >

> ps - to Dave, heard anything yet?







----------------------------

#14223 Feb 27 5:09 AM

"Dave's not here man!"



James, you're starting to telegraph your age! LOL!

Art



--- In Losmandy_users@yahoogroups.com, "cjl023 james.lacey@m...>"

james.lacey@m...> wrote: > Rod,

>

> > However, it will not do a meridan flip.

>

> My understanding is that while tracking the Gemini WILL NOT do a

> meridian flip. It will continue to track the object until a safety

> limit is hit.

>

> It might do a meridian flip if you told it to GOTO the same object

> again after it has crossed your meridian, but I don't know this

for > certain. I have never tried it.

>

> This whole meridian flip concept seems to be a continual source of

> confusion. I don't think it is as complex as people seem to think.

>

> A meridian flip is just the act of moving the OTA to the other

side > of the mount so that you can continue to track it after it has

> crossed the meridian. Of course you would not want to do this in

the > middle of a long exposure, so this is why the Gemini just

continues > to track the object until it hits a safety limit.

>

> > I have not yet "told" the scope the "local" time (it "knows"

utc), > > nor have I set any safety limits.

>

> I don't think you can tell the Gemini the "local" time. You tell

it > utc and your time zone, and it figures out local time from that.

>

> The Gemini comes with default settings for safety limits that are

> conservative. So, you don't have to ever set safety limits if you

do > not want to.

>

> > ps - to Dave, heard anything yet?

>

> ps - Dave not here :)

>

> Regards,



----------------------------

#14224 Feb 27 5:12 AM

At the risk of clouding this further...



When you say "manually" slew the scope to the other side of the

meridian, then do a GoTo... - may I assume that means you do it with

the controller? If I physically move the scope (the Jack Armstrong

method!) the Gemini obviously loses track of where it's pointing the

OTA?

Art



--- In Losmandy_users@yahoogroups.com, "Dave Sandage daves@e...>"

daves@e...> wrote: > Hi Rod,

> Dave here...

>

> James Lacey gave you a good answer on the meridian flip. It won't

> flip while tracking, but will flip when it is near the safety

limit > and you do a GOTO. However, at least with the default safety

> limits, the western safety limit is pretty far past the meridian.

> It often surprises me how often a GOTO sends me past the meridian

> without a flip. Rene's algorithm is that for targets that can be

> reached with the OTA on either side of the meridian, he will only

> flip if the object is within 10 minutes if hitting the safety

> limit. If you really want to do a GOTO for such an object (more

> than 10 minutes away from the western limit), manually slew the

> scope to the other side of the meridian, then do the GOTO.

>

> As for the RS-232 problem, Scott agreed to take a look at my

> controller box. I sent it to him, and UPS told me that he

recieved > it on 2/17. I haven't heard from him since, so I don't know what

> he's found. I've emailed him a couple times since then for an

> update, but he hasn't responded. So, I STILL don't know what's

> going on and don't have my controller back. I'll let you know

when > I finally hear from him.

>

> Dave Sandage

>

> --- In Losmandy_users@yahoogroups.com, "rod_bertelsen

> rbertelsen@e...>" rbertelsen@e...> wrote:

> > Hello group, I've been a gemini titan owner for over 700 hours

now > > w>. I've been through the setup routines concerning lat/lon;

> setting

> > utc, then in the evening running the polar assist routine (I

cannot > > see polaris in my backyard). Once I setup the telescope it

points > > great, very great. The images are rock steady. However, it will

> not

> > do a meridan flip. I'm really puzzled by this, please what have

I > > forgotten! I work mostly in the east south quad but objects in

the > > west more than 2 hours over the overhead RA, it will not flip.

I > have

> > not yet "told" the scope the "local" time (it "knows" utc), nor

> have I

> > set any safety limits. Is this the cause? - thank you in

advance - > Rod

> >

> > ps - to Dave, heard anything yet?



----------------------------

#14233 Feb 27 8:09 AM

Art,



I know. Believe it or not I think I still have my old Cheech-and-

Chong records in the attic somewhere.... Or are they 8-track tapes?



Regards,



--- In Losmandy_users@yahoogroups.com, "Art Burke aburkefl@c...>"

aburkefl@c...> wrote: > "Dave's not here man!"

>

> James, you're starting to telegraph your age! LOL!

> Art

>

> --- In Losmandy_users@yahoogroups.com, "cjl023 james.lacey@m...>"

> james.lacey@m...> wrote:

> > Rod,

> >

> > > However, it will not do a meridan flip.

> >

> > My understanding is that while tracking the Gemini WILL NOT do a

> > meridian flip. It will continue to track the object until a

safety > > limit is hit.

> >

> > It might do a meridian flip if you told it to GOTO the same

object > > again after it has crossed your meridian, but I don't know this

> for

> > certain. I have never tried it.

> >

> > This whole meridian flip concept seems to be a continual source

of > > confusion. I don't think it is as complex as people seem to think.

> >

> > A meridian flip is just the act of moving the OTA to the other

> side

> > of the mount so that you can continue to track it after it has

> > crossed the meridian. Of course you would not want to do this in

> the

> > middle of a long exposure, so this is why the Gemini just

> continues

> > to track the object until it hits a safety limit.

> >

> > > I have not yet "told" the scope the "local" time (it "knows"

> utc),

> > > nor have I set any safety limits.

> >

> > I don't think you can tell the Gemini the "local" time. You tell

> it

> > utc and your time zone, and it figures out local time from that.

> >

> > The Gemini comes with default settings for safety limits that are

> > conservative. So, you don't have to ever set safety limits if you

> do

> > not want to.

> >

> > > ps - to Dave, heard anything yet?

> >

> > ps - Dave not here :)

> >

> > Regards,







----------------------------

#14234 Feb 27 8:53 AM

Art,

Whoops, yes, I meant with the buttons on the hand controller. I'm

so used to my Gemini now that I don't even think about pushing the

scope around by hand any more. That's what my dob is for g>.



Dave



--- In Losmandy_users@yahoogroups.com, "Art Burke aburkefl@c...>"

aburkefl@c...> wrote: > At the risk of clouding this further...

>

> When you say "manually" slew the scope to the other side of the

> meridian, then do a GoTo... - may I assume that means you do it

with > the controller? If I physically move the scope (the Jack Armstrong

> method!) the Gemini obviously loses track of where it's pointing

the > OTA?

> Art

>

> --- In Losmandy_users@yahoogroups.com, "Dave Sandage daves@e...>"

> daves@e...> wrote:

> > Hi Rod,

> > Dave here...

> >

> > James Lacey gave you a good answer on the meridian flip. It

won't > > flip while tracking, but will flip when it is near the safety

> limit

> > and you do a GOTO. However, at least with the default safety

> > limits, the western safety limit is pretty far past the

meridian. > > It often surprises me how often a GOTO sends me past the

meridian > > without a flip. Rene's algorithm is that for targets that can

be > > reached with the OTA on either side of the meridian, he will

only > > flip if the object is within 10 minutes if hitting the safety

> > limit. If you really want to do a GOTO for such an object (more

> > than 10 minutes away from the western limit), manually slew the

> > scope to the other side of the meridian, then do the GOTO.

> >

> > As for the RS-232 problem, Scott agreed to take a look at my

> > controller box. I sent it to him, and UPS told me that he

> recieved

> > it on 2/17. I haven't heard from him since, so I don't know

what > > he's found. I've emailed him a couple times since then for an

> > update, but he hasn't responded. So, I STILL don't know what's

> > going on and don't have my controller back. I'll let you know

> when

> > I finally hear from him.

> >

> > Dave Sandage

> >

> > --- In Losmandy_users@yahoogroups.com, "rod_bertelsen

> > rbertelsen@e...>" rbertelsen@e...> wrote:

> > > Hello group, I've been a gemini titan owner for over 700 hours

> now

> > > w>. I've been through the setup routines concerning lat/lon;

> > setting

> > > utc, then in the evening running the polar assist routine (I

> cannot

> > > see polaris in my backyard). Once I setup the telescope it

> points

> > > great, very great. The images are rock steady. However, it

will > > not

> > > do a meridan flip. I'm really puzzled by this, please what

have > I

> > > forgotten! I work mostly in the east south quad but objects

in > the

> > > west more than 2 hours over the overhead RA, it will not

flip. > I

> > have

> > > not yet "told" the scope the "local" time (it "knows" utc),

nor > > have I

> > > set any safety limits. Is this the cause? - thank you in

> advance -

> > Rod

> > >

> > > ps - to Dave, heard anything yet?



----------------------------

#14235 Feb 27 8:58 AM

Rod,

Just heard back from Scott. He sent me a new unit (just arrived

tonight). The RS-232 on the new unit works just fine. He was

unable to root cause the problem on the old board, but is meeting

with Rene' this weekend to go over it. Rene' has the tools to

diagnose the problem. Hopefully they will determine if this is a

problem specific to that one board, or a more general problem. I'll

let you know as soon as I hear back.



Dave



--- In Losmandy_users@yahoogroups.com, "rod_bertelsen

rbertelsen@e...>" rbertelsen@e...> wrote: > ps - to Dave, heard anything yet?



----------------------------

#14236 Feb 27 10:04 AM

----- Original Message -----

From: james.lacey@...>

Subject: [Losmandy_users] Re: A newbie question during cloudy skies

concerning the meridian flip







> I know. Believe it or not I think I still have my old Cheech-and-

> Chong records in the attic somewhere.... Or are they 8-track tapes?



Heck, I'll go you one better: I remember friends who had dash mounted record

players in their cars (didn't want to hit a pothole.) Also remember playing

around with wire recorders in high school g>! (Also remember party lines

growing up in L.A., but that's a different story...)



Jim Girard



----------------------------

#14237 Feb 27 11:43 AM

Party lines in LA?



No way?



Man, we have come so far in some ways, and in others, well we better

not go there I guess.



Just to keep this legit, do you use a focal reducer with your FS102

Jim, or do you shoot at f8? Just curious really.



Regards,

--- In Losmandy_users@yahoogroups.com, Jim Girard argojg@c...> wrote:

>

> ----- Original Message -----

> From: james.lacey@m...>

> Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> concerning the meridian flip

>

>

>

> > I know. Believe it or not I think I still have my old Cheech-and-

> > Chong records in the attic somewhere.... Or are they 8-track

tapes?

>

> Heck, I'll go you one better: I remember friends who had dash

mounted record

> players in their cars (didn't want to hit a pothole.) Also remember

playing

> around with wire recorders in high school g>! (Also remember party

lines

> growing up in L.A., but that's a different story...)

>

> Jim Girard







----------------------------

#14238 Feb 27 2:40 PM

Hi All - Amazing ... meridian flips to sister mary elephant!! I love

it! g> I think I got it (regarding the meridian flip). Regarding

the local time issue; I think I can actually set it (according to the

version 3 manual). I know for sure that the gemini knows the correct

ut and st, it points great once the model is established but it

definitely "thinks" it's on the west and not the east coast in lt. -

thanks everybody! - Rod - but PS - my board seems to have the same

bug that Dave's had (regarding the rs232 port). Perhaps other things

are related? Good eve.







--- In Losmandy_users@yahoogroups.com, "cjl023 james.lacey@m...>"

james.lacey@m...> wrote: > Party lines in LA?

>

> No way?

>

> Man, we have come so far in some ways, and in others, well we better

> not go there I guess.

>

> Just to keep this legit, do you use a focal reducer with your FS102

> Jim, or do you shoot at f8? Just curious really.

>

> Regards,

>

> --- In Losmandy_users@yahoogroups.com, Jim Girard argojg@c...> wrote:

> >

> > ----- Original Message -----

> > From: james.lacey@m...>

> > Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> > concerning the meridian flip

> >

> >

> >

> > > I know. Believe it or not I think I still have my old Cheech-and-

> > > Chong records in the attic somewhere.... Or are they 8-track

> tapes?

> >

> > Heck, I'll go you one better: I remember friends who had dash

> mounted record

> > players in their cars (didn't want to hit a pothole.) Also remember

> playing

> > around with wire recorders in high school g>! (Also remember party

> lines

> > growing up in L.A., but that's a different story...)

> >

> > Jim Girard



----------------------------

#14241 Feb 27 3:47 PM

Hi Dave - great news!! I hope for the same. I talked to Scott just prior to

his departure for Germany. Scott said that there was only one other person

with the same symptoms as myself (refering to you). I really would like to

get this cleared up ASAP but I'd like for a good permanent solution, not a

bandaide. In the meantime - I'm taking already better images unguided with

this mount than I was ever able to do with the original equipment. - take

care - Rod





----- Original Message -----

From: daves@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, February 27, 2003 11:58 AM

Subject: [Losmandy_users] RS-232 Gemini issue (was "...the meridian flip")





> Rod,

> Just heard back from Scott. He sent me a new unit (just arrived

> tonight). The RS-232 on the new unit works just fine. He was

> unable to root cause the problem on the old board, but is meeting

> with Rene' this weekend to go over it. Rene' has the tools to

> diagnose the problem. Hopefully they will determine if this is a

> problem specific to that one board, or a more general problem. I'll

> let you know as soon as I hear back.

>

> Dave

>

> --- In Losmandy_users@yahoogroups.com, "rod_bertelsen

> rbertelsen@e...>" rbertelsen@e...> wrote:

> > ps - to Dave, heard anything yet?

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>

>

> Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>



----------------------------

#14243 Feb 27 5:13 PM

> Just to keep this legit, do you use a focal reducer with your FS102

> Jim, or do you shoot at f8? Just curious really.

>



I am not sure if Jim uses a focal reducer with his FS102, but I do quite

often. Very nice wide fields and the faster focal ratio helps suck photons.

Do you have a particular question about it?



Tom Carrico

www.ccdargo.com



----------------------------

#14245 Feb 27 5:36 PM

Hey Tom,



No. Was just wondering what focal ratio Jim was using, since he

seems to have such great guiding in his shots.



I guess attaching the F/R moves your balance point a little farther

back towards the F/R no?



Regards,



--- In Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

wrote: > >

> > Just to keep this legit, do you use a focal reducer with your

FS102 > > Jim, or do you shoot at f8? Just curious really.

> >

>

> I am not sure if Jim uses a focal reducer with his FS102, but I do

quite > often. Very nice wide fields and the faster focal ratio helps suck

photons. > Do you have a particular question about it?

>

> Tom Carrico

> www.ccdargo.com



----------------------------

#14246 Feb 27 5:37 PM

With the focal reducer in place, you have to move the camera in even closer

to the telescope tube. The movement in is about 1.5 inches, which offsets

the weight of the focal reducer and then some.

Tom Carrico

www.ccdargo.com ----- Original Message -----

From: james.lacey@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, February 27, 2003 5:36 PM

Subject: [Losmandy_users] Re: A newbie question during cloudy skies

concerning the meridian flip





> Hey Tom,

>

> No. Was just wondering what focal ratio Jim was using, since he

> seems to have such great guiding in his shots.

>

> I guess attaching the F/R moves your balance point a little farther

> back towards the F/R no?

>

> Regards,

>

> --- In Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

> wrote:

> > >

> > > Just to keep this legit, do you use a focal reducer with your

> FS102

> > > Jim, or do you shoot at f8? Just curious really.

> > >

> >

> > I am not sure if Jim uses a focal reducer with his FS102, but I do

> quite

> > often. Very nice wide fields and the faster focal ratio helps suck

> photons.

> > Do you have a particular question about it?

> >

> > Tom Carrico

> > www.ccdargo.com

>

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>

>

> Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>

>







----------------------------

#14247 Feb 27 5:52 PM

Tom,



But of course. I didn't think about the change in the focal plane.



That's actually good news. I have all my stuff set-up for imaging at

f/8 and I was hoping that switching to f/6 did not cause a huge

difference in the balance point but was not sure.



The F/R for the FS102 is real beastie. Probably weighs about 1.5lbs

or so?



Take Care,



--- Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...> wrote: > With the focal reducer in place, you have to move the camera in

even closer > to the telescope tube. The movement in is about 1.5 inches, which

offsets > the weight of the focal reducer and then some.

> Tom Carrico

> www.ccdargo.com

> ----- Original Message -----

> From: james.lacey@m...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Thursday, February 27, 2003 5:36 PM

> Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> concerning the meridian flip

>

>

> > Hey Tom,

> >

> > No. Was just wondering what focal ratio Jim was using, since he

> > seems to have such great guiding in his shots.

> >

> > I guess attaching the F/R moves your balance point a little

farther > > back towards the F/R no?

> >

> > Regards,

> >

> > --- In Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

> > wrote:

> > > >

> > > > Just to keep this legit, do you use a focal reducer with your

> > FS102

> > > > Jim, or do you shoot at f8? Just curious really.

> > > >

> > >

> > > I am not sure if Jim uses a focal reducer with his FS102, but

I do > > quite

> > > often. Very nice wide fields and the faster focal ratio helps

suck > > photons.

> > > Do you have a particular question about it?

> > >

> > > Tom Carrico

> > > www.ccdargo.com

> >

> >

> >

> > To unsubscribe from this group, send an email to:

> > Losmandy_users-unsubscribe@egroups.com

> >

> >

> >

> > Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/ > >

> >

> >



----------------------------

#14248 Feb 27 6:07 PM

Maybe a pound, but it is big. Without the FR, I use a long SCT t-adapter

with my Feldstein adapter to connect my ST-10/CFW-8. With the focal reducer,

the focal plane moves in far enough that I have to use a much shorter

t-adapter. Anacortes carries them.

Tom Carrico

www.ccdargo.com ----- Original Message -----

From: james.lacey@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, February 27, 2003 5:52 PM

Subject: [Losmandy_users] Re: A newbie question during cloudy skies

concerning the meridian flip





> Tom,

>

> But of course. I didn't think about the change in the focal plane.

>

> That's actually good news. I have all my stuff set-up for imaging at

> f/8 and I was hoping that switching to f/6 did not cause a huge

> difference in the balance point but was not sure.

>

> The F/R for the FS102 is real beastie. Probably weighs about 1.5lbs

> or so?

>

> Take Care,

>

> --- Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...> wrote:

> > With the focal reducer in place, you have to move the camera in

> even closer

> > to the telescope tube. The movement in is about 1.5 inches, which

> offsets

> > the weight of the focal reducer and then some.

> > Tom Carrico

> > www.ccdargo.com

> > ----- Original Message -----

> > From: james.lacey@m...>

> > To: Losmandy_users@yahoogroups.com>

> > Sent: Thursday, February 27, 2003 5:36 PM

> > Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> > concerning the meridian flip

> >

> >

> > > Hey Tom,

> > >

> > > No. Was just wondering what focal ratio Jim was using, since he

> > > seems to have such great guiding in his shots.

> > >

> > > I guess attaching the F/R moves your balance point a little

> farther

> > > back towards the F/R no?

> > >

> > > Regards,

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

> > > wrote:

> > > > >

> > > > > Just to keep this legit, do you use a focal reducer with your

> > > FS102

> > > > > Jim, or do you shoot at f8? Just curious really.

> > > > >

> > > >

> > > > I am not sure if Jim uses a focal reducer with his FS102, but

> I do

> > > quite

> > > > often. Very nice wide fields and the faster focal ratio helps

> suck

> > > photons.

> > > > Do you have a particular question about it?

> > > >

> > > > Tom Carrico

> > > > www.ccdargo.com

> > >

> > >

> > >

> > > To unsubscribe from this group, send an email to:

> > > Losmandy_users-unsubscribe@egroups.com

> > >

> > >

> > >

> > > Your use of Yahoo! Groups is subject to

> docs.yahoo.com/info/terms/

> > >

> > >

> > >

>

>

> To unsubscribe from this group, send an email to:

> Losmandy_users-unsubscribe@egroups.com

>

>

>

> Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>

>







----------------------------

#14249 Feb 27 6:23 PM

Tom,



Ouch!



I connect a Taurus Tracker 3 OAG to my FS102 using a feldstein

adapter, so hopefully the focal plane will not move in so much that

I cannot acheive prime focus (which is a challenge for me as I'm

sure you know :)



In any case, I'll enjoy using it visually too. I have not been able

to get out in over a month due to schedule and Weather. I probably

don't even remember how to hook everything up anymore *-}



Take Care,



--- In Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

wrote: > Maybe a pound, but it is big. Without the FR, I use a long SCT t-

adapter > with my Feldstein adapter to connect my ST-10/CFW-8. With the

focal reducer, > the focal plane moves in far enough that I have to use a much

shorter > t-adapter. Anacortes carries them.

> Tom Carrico

> www.ccdargo.com

> ----- Original Message -----

> From: james.lacey@m...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Thursday, February 27, 2003 5:52 PM

> Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> concerning the meridian flip

>

>

> > Tom,

> >

> > But of course. I didn't think about the change in the focal

plane. > >

> > That's actually good news. I have all my stuff set-up for

imaging at > > f/8 and I was hoping that switching to f/6 did not cause a huge

> > difference in the balance point but was not sure.

> >

> > The F/R for the FS102 is real beastie. Probably weighs about

1.5lbs > > or so?

> >

> > Take Care,

> >

> > --- Losmandy_users@yahoogroups.com, "Tom Carrico" tom@c...>

wrote: > > > With the focal reducer in place, you have to move the camera in

> > even closer

> > > to the telescope tube. The movement in is about 1.5 inches,

which > > offsets

> > > the weight of the focal reducer and then some.

> > > Tom Carrico

> > > www.ccdargo.com

> > > ----- Original Message -----

> > > From: james.lacey@m...>

> > > To: Losmandy_users@yahoogroups.com>

> > > Sent: Thursday, February 27, 2003 5:36 PM

> > > Subject: [Losmandy_users] Re: A newbie question during cloudy

skies > > > concerning the meridian flip

> > >

> > >

> > > > Hey Tom,

> > > >

> > > > No. Was just wondering what focal ratio Jim was using, since

he > > > > seems to have such great guiding in his shots.

> > > >

> > > > I guess attaching the F/R moves your balance point a little

> > farther

> > > > back towards the F/R no?

> > > >

> > > > Regards,

> > > >

> > > > --- In Losmandy_users@yahoogroups.com, "Tom Carrico"

tom@c...> > > > > wrote:

> > > > > >

> > > > > > Just to keep this legit, do you use a focal reducer with

your > > > > FS102

> > > > > > Jim, or do you shoot at f8? Just curious really.

> > > > > >

> > > > >

> > > > > I am not sure if Jim uses a focal reducer with his FS102,

but > > I do

> > > > quite

> > > > > often. Very nice wide fields and the faster focal ratio

helps > > suck

> > > > photons.

> > > > > Do you have a particular question about it?

> > > > >

> > > > > Tom Carrico

> > > > > www.ccdargo.com

> > > >

> > > >

> > > >

> > > > To unsubscribe from this group, send an email to:

> > > > Losmandy_users-unsubscribe@egroups.com

> > > >

> > > >

> > > >

> > > > Your use of Yahoo! Groups is subject to

> > docs.yahoo.com/info/terms/

> > > >

> > > >

> > > >

> >

> >

> > To unsubscribe from this group, send an email to:

> > Losmandy_users-unsubscribe@egroups.com

> >

> >

> >

> > Your use of Yahoo! Groups is subject to

docs.yahoo.com/info/terms/ > >

> >

> >



----------------------------

#14250 Feb 28 4:07 AM

That got a chuckle out of me! At one point I really, really, wanted

a dob - aperture fever! A guy next to me at a star party had a

Starmaster 14". I didn't realize he was tracking. He showed us (my

girlfriend was there at her first star party) M13 and I took a quick

peek, then stepped away so someone else could have a peek. A couple

minutes went by and no one touched the scope. When I peeked in again

I could still see M13 in the center of the FOV. I said something and

then he said he had tracking motors. I was all excited until...



I checked out a number of the Johnsonian, Poncet, etc. platforms but

wasn't really happy about what you have to go through. They

obviously work for imaging (and that's my ultimate objective in all

this) for there's one thing I still don't understand - just in case

anyone here knows. A Poncet platform well allow the DOB to track

equatorially for anywhere from 30 to 90 minutes (depending on

design, quality, alignment, etc.), then it has to be "reset." Since

you can't move the DOB all over the sky (like aligning a GEM) to re-

align, what's the process for getting re-aligned for another

tracking session?

Art



--- In Losmandy_users@yahoogroups.com, "Dave Sandage daves@e...>"

daves@e...> wrote: > Art,

> Whoops, yes, I meant with the buttons on the hand controller. I'm

> so used to my Gemini now that I don't even think about pushing the

> scope around by hand any more. That's what my dob is for g>.

>

> Dave

>

> --- In Losmandy_users@yahoogroups.com, "Art Burke aburkefl@c...>"

> aburkefl@c...> wrote:

> > At the risk of clouding this further...

> >

> > When you say "manually" slew the scope to the other side of the

> > meridian, then do a GoTo... - may I assume that means you do it

> with

> > the controller? If I physically move the scope (the Jack

Armstrong > > method!) the Gemini obviously loses track of where it's pointing

> the

> > OTA?

> > Art

> >

> > --- In Losmandy_users@yahoogroups.com, "Dave Sandage

daves@e...>" > > daves@e...> wrote:

> > > Hi Rod,

> > > Dave here...

> > >

> > > James Lacey gave you a good answer on the meridian flip. It

> won't

> > > flip while tracking, but will flip when it is near the safety

> > limit

> > > and you do a GOTO. However, at least with the default safety

> > > limits, the western safety limit is pretty far past the

> meridian.

> > > It often surprises me how often a GOTO sends me past the

> meridian

> > > without a flip. Rene's algorithm is that for targets that can

> be

> > > reached with the OTA on either side of the meridian, he will

> only

> > > flip if the object is within 10 minutes if hitting the safety

> > > limit. If you really want to do a GOTO for such an object

(more > > > than 10 minutes away from the western limit), manually slew

the > > > scope to the other side of the meridian, then do the GOTO.

> > >

> > > As for the RS-232 problem, Scott agreed to take a look at my

> > > controller box. I sent it to him, and UPS told me that he

> > recieved

> > > it on 2/17. I haven't heard from him since, so I don't know

> what

> > > he's found. I've emailed him a couple times since then for an

> > > update, but he hasn't responded. So, I STILL don't know

what's > > > going on and don't have my controller back. I'll let you know

> > when

> > > I finally hear from him.

> > >

> > > Dave Sandage

> > >

> > > --- In Losmandy_users@yahoogroups.com, "rod_bertelsen

> > > rbertelsen@e...>" rbertelsen@e...> wrote:

> > > > Hello group, I've been a gemini titan owner for over 700

hours > > now

> > > > w>. I've been through the setup routines concerning

lat/lon; > > > setting

> > > > utc, then in the evening running the polar assist routine (I

> > cannot

> > > > see polaris in my backyard). Once I setup the telescope it

> > points

> > > > great, very great. The images are rock steady. However, it

> will

> > > not

> > > > do a meridan flip. I'm really puzzled by this, please what

> have

> > I

> > > > forgotten! I work mostly in the east south quad but objects

> in

> > the

> > > > west more than 2 hours over the overhead RA, it will not

> flip.

> > I

> > > have

> > > > not yet "told" the scope the "local" time (it "knows" utc),

> nor

> > > have I

> > > > set any safety limits. Is this the cause? - thank you in

> > advance -

> > > Rod

> > > >

> > > > ps - to Dave, heard anything yet?







----------------------------

#14251 Feb 28 4:11 AM

Never knew anyone who had the record player in the car, but I saw

one advertised once.



A friend who lived a couple houses away when I was about 13 had a

wire recorder - still has it! He also has one of those old players

that takes cylinders! About the only thing really old I have any

more is/are some slide rules!



In my brief life (I'm 58) I've never owned: an 8-track player, a

citizen's band radio, a leisure suit or a Nehru jacket! However,

don't ask me about some of my other purchases - like a Digital

Compact Cassette!

Art



--- In Losmandy_users@yahoogroups.com, Jim Girard argojg@c...>

wrote: >

> ----- Original Message -----

> From: james.lacey@m...>

> Subject: [Losmandy_users] Re: A newbie question during cloudy skies

> concerning the meridian flip

>

>

>

> > I know. Believe it or not I think I still have my old Cheech-and-

> > Chong records in the attic somewhere.... Or are they 8-track

tapes? >

> Heck, I'll go you one better: I remember friends who had dash

mounted record > players in their cars (didn't want to hit a pothole.) Also

remember playing > around with wire recorders in high school g>! (Also remember

party lines > growing up in L.A., but that's a different story...)

>

> Jim Girard



----------------------------

#14252 Feb 28 4:17 AM

With Level 3 on the Gemini, you can identify your time zone. If the

battery dies (the CMOS battery) the default coordinates are for

Scott's shop in California.



It's kind of puzzling to me why the Gemini would need to know your

local time or your local time zone. With your lat/lon and UTC it

should have everything it needs. The trigonometry associated with

finding the first alignment star should not involve your local time -

actually, it will, but it should already know what time it is where

you are!



Besides, "local time" is sort of a misnomer. The true "local time"

is also contingent on where (how far east or west of the time-zone-

determinant-longitude) you really are. In the case of the Gemini, it

only asks for UTC and your time zone.



Who actually wrote the Gemini program - bet he/she knows!!

Art



--- In Losmandy_users@yahoogroups.com, "rod_bertelsen

rbertelsen@e...>" rbertelsen@e...> wrote: > Hi All - Amazing ... meridian flips to sister mary elephant!! I

love > it! g> I think I got it (regarding the meridian flip). Regarding

> the local time issue; I think I can actually set it (according to

the > version 3 manual). I know for sure that the gemini knows the

correct > ut and st, it points great once the model is established but it

> definitely "thinks" it's on the west and not the east coast in

lt. - > thanks everybody! - Rod - but PS - my board seems to have the

same > bug that Dave's had (regarding the rs232 port). Perhaps other

things > are related? Good eve.

>

>

>

> --- In Losmandy_users@yahoogroups.com, "cjl023 james.lacey@m...>"

> james.lacey@m...> wrote:

> > Party lines in LA?

> >

> > No way?

> >

> > Man, we have come so far in some ways, and in others, well we

better > > not go there I guess.

> >

> > Just to keep this legit, do you use a focal reducer with your

FS102 > > Jim, or do you shoot at f8? Just curious really.

> >

> > Regards,

> >

> > --- In Losmandy_users@yahoogroups.com, Jim Girard argojg@c...>

wrote: > > >

> > > ----- Original Message -----

> > > From: james.lacey@m...>

> > > Subject: [Losmandy_users] Re: A newbie question during cloudy

skies > > > concerning the meridian flip

> > >

> > >

> > >

> > > > I know. Believe it or not I think I still have my old Cheech-

and- > > > > Chong records in the attic somewhere.... Or are they 8-track

> > tapes?

> > >

> > > Heck, I'll go you one better: I remember friends who had dash

> > mounted record

> > > players in their cars (didn't want to hit a pothole.) Also

remember > > playing

> > > around with wire recorders in high school g>! (Also remember

party > > lines

> > > growing up in L.A., but that's a different story...)

> > >

> > > Jim Girard



----------------------------

#19129 Feb 15 3:44 AM

Hi all,



we get G-11 mount, which we plan to use for robotice telescope, taking

CCD images. We process them so they get astrometry (correct true

coordinates based on stars position and so). For prcocessing I need to

know if the mount was east or west of meridian - that changes

orientation of the images.



Is there any way how to get that from Gemini throught serial port? I

was looking throught the manual, but there is nothing about it.



Petr Kubanek, RTS2 co-author

lascaux.asu.cas.cz/bartdb



----------------------------

#19140 Feb 15 9:42 AM

Peter, I assume you're thinking about the Gemini system used with the

G11.



As far as I know, there's currently no way of getting which side of

the meridian the mount is on from the Gemini serial interface.



Next version of Gemini, Level 4, will have such a function, at least

according to the early specification of the serial protocol.



Even without this new function, if you'll be using an astrometric

solution to determine pointing location, that should also give you

the orientation of the telescope.



Hope this helps,



-Paul



--- In Losmandy_users@yahoogroups.com, "Petr Kubanek" pkubanek@e...>

wrote: > Hi all,

>

> we get G-11 mount, which we plan to use for robotice telescope,

taking > CCD images. We process them so they get astrometry (correct true

> coordinates based on stars position and so). For prcocessing I need

to > know if the mount was east or west of meridian - that changes

> orientation of the images.

>

> Is there any way how to get that from Gemini throught serial port? I

> was looking throught the manual, but there is nothing about it.

>

> Petr Kubanek, RTS2 co-author

> lascaux.asu.cas.cz/bartdb







----------------------------

#20288 Apr 27, 2004

Hey Paul,



--- Paul K pkane2001@...> wrote: > Two reasons for losing the pointing model are a weak internal

> battery and an intermittent power loss.

>

> Replace the internal 3v battery just in case, and check your power

> connector to make sure it's tight and clean.



Just to be safe, I'll look for another battery tomorrow. But as to how

an intermittent power loss could cause loss of the model, doesn't make

sense to me. My pointing losses are apparent right after power up. If

there is a power loss during the time (10-14 days) the mount is

inactive, well, isn't that what the internal battery is for? To retain

all the user input data while the power is not available to the mount?

Anyway, that's my limited understanding of it's purpose.



Of course, I don't see any info in the manual regarding the stupid

thing. So, I'll assume that it's a type of battery readily available at

most well stocked stores. Please reassure me that it's not one of those

special order type of batteries.



You know, I have one more thing I'd like to know more about. Meridian

flips. How and when do they occur? Is there any warning? Can the

operator perform one at his/her discretion (assuming the mount is in a

proper location of course)?



Thanks,

Alan









---------------

Do you Yahoo!?

Win a $20,000 Career Makeover at Yahoo! HotJobs

hotjobs.sweepstakes.yahoo.com/careermakeover



----------------------------

#20289 Apr 27, 2004

Hi Alan,



The battery is a widely available 3v Li battery CR2032. You should be

able to find it at RadioShack, local supermarket or drug store.



What I believe happens is when the power is lost briefly, Gemini

attempts to save all settings to CMOS memory. If the power comes back

or maybe is lost again, there's sometimes garbage or incomplete

information saved resulting in loss of model and all local settings.



This happened to me a few times until I figured out that my power

connector (older Gemini) was the wrong size g>



Meridian flip becomes necessary when your telescope comes too close

to the mount on the west side. This will happen every time as long as

you leave your mount tracking in RA. Gemini has safety limits that

will beep and eventually stop the tracking when the mount gets too

far west. You can change these limits to account for your praticular

telescope/mount combination.



You can, of course, at any time manually ask the mount to move to the

east side.



When you perform a Goto command, the mount will check if the

destination exceeds the western safety limit, and if it does, it will

automatically execute a meridian flip and position the telescope on

the east side of the mount.



Hope this helps,



-Paul





--- In Losmandy_users@yahoogroups.com, Alan Voetsch alanv12952@y...>

wrote: > Hey Paul,

>

> --- Paul K pkane2001@h...> wrote:

> > Two reasons for losing the pointing model are a weak internal

> > battery and an intermittent power loss.

> >

> > Replace the internal 3v battery just in case, and check your

power > > connector to make sure it's tight and clean.

>

> Just to be safe, I'll look for another battery tomorrow. But as to

how > an intermittent power loss could cause loss of the model, doesn't

make > sense to me. My pointing losses are apparent right after power up.

If > there is a power loss during the time (10-14 days) the mount is

> inactive, well, isn't that what the internal battery is for? To

retain > all the user input data while the power is not available to the

mount? > Anyway, that's my limited understanding of it's purpose.

>

> Of course, I don't see any info in the manual regarding the stupid

> thing. So, I'll assume that it's a type of battery readily

available at > most well stocked stores. Please reassure me that it's not one of

those > special order type of batteries.

>

> You know, I have one more thing I'd like to know more about.

Meridian > flips. How and when do they occur? Is there any warning? Can the

> operator perform one at his/her discretion (assuming the mount is

in a > proper location of course)?

>

> Thanks,

> Alan

>



----------------------------

#20290 Apr 27, 2004

Hey Paul,



--- Paul K pkane2001@...> wrote: > The battery is a widely available 3v Li battery CR2032. You should be

>

> able to find it at RadioShack, local supermarket or drug store.



All right, I believe I've actually even bought those before. Thanks for

the MF info.



Alan















---------------

Do you Yahoo!?

Win a $20,000 Career Makeover at Yahoo! HotJobs

hotjobs.sweepstakes.yahoo.com/careermakeover



----------------------------

#21307 Jun 27, 2004

Just want to thank everyone for all the data. Good thing I'm retired. I see

that now I also may need two sets of flats. This is when I start to image.

I'm still in the infancy stage of learning about a GEM, and Gemini. In fact

I'm going backwards. I just could not get the mount to do a meridian flip. I

was building a pointing model on one side then issued a goto bright star on

the other side of the meridian but it did not want to take the long way

around. Had to interrupt the slew. Shut off Gemini, COLD restarted, and

started a new pointing model. But again, when attempting to add a star on

the other side of the meridian, no flip. I had to give up since I was doing

something basically wrong. Each time though, the portion of the model WAS

getting better. So it didn't appear to be incorrect Time, Location, etc.

Motors ran cool, no problems other than operator error.

Regards - Bob

www.skyfoto.com







----------------------------

#21309 Jun 27, 2004

Bob;



What Gemini does is try to take the shortest rout to the desired

destination. If you put your Safety Limit, an electronic stop, in the way

the mount performs a Meridian flip. Somehow you either forgot to set it,

like I did, or it got wiped out. Re-establish your Safety Limits and you

will Meridian Flip.



Don't ask me how Charlie or Alan guide well past the Meridian. I've

seen them imaging with their counterweights high up in the sky, ~45deg high.

Maybe they may have set the Safety Limits well past the Meridian, with the

OTA 'under' the mounts horizontal position. But if that's the case wouldn't

they then run into problems anyway when they Slew and hit the stop point

with the Safety Limit way down there? But they don't seem to.



Charlie / Alan, care to explain?...joe :)





"May You Go Among The Imperishable Stars"



Joe Mize: jmize@...

StarFields Observatory www.svic.net/jmize

Chiefland, FL 29:24'33.4"N 82:51'37.7"W

Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

----- Original Message -----

From: "bob allevo" bob.allevo@...>

To: "Titan_Mount" Titan_Mount@yahoogroups.com>; "Losmandy_users"

Losmandy_users@yahoogroups.com>

Sent: Sunday, June 27, 2004 9:20 AM

Subject: [Losmandy_users] Meridian Flip Feedback





> Just want to thank everyone for all the data. Good thing I'm retired. I

see

> that now I also may need two sets of flats. This is when I start to image.

> I'm still in the infancy stage of learning about a GEM, and Gemini. In

fact

> I'm going backwards. I just could not get the mount to do a meridian flip.

I

> was building a pointing model on one side then issued a goto bright star

on

> the other side of the meridian but it did not want to take the long way

> around. Had to interrupt the slew. Shut off Gemini, COLD restarted, and

> started a new pointing model. But again, when attempting to add a star on

> the other side of the meridian, no flip. I had to give up since I was

doing

> something basically wrong. Each time though, the portion of the model WAS

> getting better. So it didn't appear to be incorrect Time, Location, etc.

> Motors ran cool, no problems other than operator error.

> Regards - Bob

> www.skyfoto.com

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>



----------------------------

#21311 Jun 27, 2004

Joe

You are right, I set my safety limits pretty aggressively so that I can image

well past Meridian without a flip. When I do a flip, I usually manually slew

the scope past the CWD position on the other side, then GoTo the object.

Gemini takes the shortest route the the object, which will now be on the opposite

side.

Don't ask me why, but some of my best guiding seems to occur with my CWs up

in the air, and I can usually get in 1.5 hours after Meridian without a crash.



Charlie

l



In a message dated 6/27/2004 9:51:49 AM Eastern Standard Time, jmize@...

writes:

Bob;



What Gemini does is try to take the shortest rout to the desired

destination. If you put your Safety Limit, an electronic stop, in the way

the mount performs a Meridian flip. Somehow you either forgot to set it,

like I did, or it got wiped out. Re-establish your Safety Limits and you

will Meridian Flip.



Don't ask me how Charlie or Alan guide well past the Meridian. I've

seen them imaging with their counterweights high up in the sky, ~45deg high.

Maybe they may have set the Safety Limits well past the Meridian, with the

OTA 'under' the mounts horizontal position. But if that's the case wouldn't

they then run into problems anyway when they Slew and hit the stop point

with the Safety Limit way down there? But they don't seem to.



Charlie / Alan, care to explain?...joe :)





[Non-text portions of this message have been removed]



----------------------------

#22888 Oct 27, 2004

I have a G-11/Gemini level 3.103. I have set the saftey limits in

east and west.Most of my imaging is just about directly overhead.

The OTA for what ever reason always slews the the extreme west side

when I perform a goto command. Once the alarm rings that it has

reached

its saftey limit on the west side of the mount...I will give a goto

command to the same object...but instead of moving to the other side

of the mount it...goes right back to where it started and the alarm

sounds agin.I have even slewed by hand (after waiting 30 minutes)to

the eastern side of the mount and then perform a goto command ...and

it still does not flip. It slews all the way back to to the other

side of the mount where its limit had been reached. Am I missing

something here? Their is no way to get the OTA to image from the

eastern side of the mount unless I manually put it there.Thanks,

Wayne



----------------------------

#22890 Oct 27, 2004

Hi Wayne,



How big is your angle between the eastern and the western limit ?

less than 180. or more than 180. ?



If you say that your imaging is nearly directly overhead than maybe

your western and eastern limit is too short and you can not image

therefore an object at the meridien ?



As far as what I have learned is that to get a star at the meridien

your RA axis is horizontal. If the angle in which your RA axis is

moving is only 170. you are missing 5. from each side of the meridien.



If your angle is about 190., which should be possible, all depends

what is hanging on the side of the OTA, then you should have no

problem.



regards Rainer





--- In Losmandy_users@yahoogroups.com, "Wayne Cooper" coopersx@c...>

wrote: >

> I have a G-11/Gemini level 3.103. I have set the saftey limits in

> east and west.Most of my imaging is just about directly overhead.

> The OTA for what ever reason always slews the the extreme west side

> when I perform a goto command. Once the alarm rings that it has

> reached

> its saftey limit on the west side of the mount...I will give a goto

> command to the same object...but instead of moving to the other

side > of the mount it...goes right back to where it started and the alarm

> sounds agin.I have even slewed by hand (after waiting 30 minutes)to

> the eastern side of the mount and then perform a goto

command ...and > it still does not flip. It slews all the way back to to the other

> side of the mount where its limit had been reached. Am I missing

> something here? Their is no way to get the OTA to image from the

> eastern side of the mount unless I manually put it there.Thanks,

> Wayne







----------------------------

#22894 Oct 27, 2004

--- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...> wrote: >

> Hi Wayne,

>

> How big is your angle between the eastern and the western limit ?

> less than 180. or more than 180. ?



More then 180. I have set both limits a little further then default

on both sides of the mount.



If you say that your imaging is nearly directly overhead than maybe > your western and eastern limit is too short and you can not image

> therefore an object at the meridien ?



I have no problem imgaging at the meridian. But when the scope is on

the west side of the monut...imaging straight up....and almost ready

to hit the leg,etc..I want to continue imaging but can't. the reason

being it wont do a goto from the other side of the mount. After

moving the scope so that the alarm stops sounding...i enter a goto

command...the scope goes right back to where it started...ready to

hit the leg on the west side of the

mount...even after waiting a good 30 minutes..then manually slewing

the scope all the way to the east and entering another goto command.

Goes right back to almost hitting the leg on the west.



As far as what I have learned is that to get a star at the meridien > your RA axis is horizontal. If the angle in which your RA axis is

> moving is only 170. you are missing 5. from each side of the

meridien.



Sorry. I may be misreading your solution or I may not have stated

my problem correctly. Let me know if I may not be following this

right. I think the angles that you mention may not be the cause. If

so

let me know. Sincerely, Wayne



If your angle is about 190., which should be possible, all

depends > what is hanging on the side of the OTA, then you should have no

> problem.

>

> regards Rainer

>

>

> --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

coopersx@c...> > wrote:

> >

> > I have a G-11/Gemini level 3.103. I have set the saftey limits

in > > east and west.Most of my imaging is just about directly

overhead. > > The OTA for what ever reason always slews the the extreme west

side > > when I perform a goto command. Once the alarm rings that it has

> > reached

> > its saftey limit on the west side of the mount...I will give a

goto > > command to the same object...but instead of moving to the other

> side

> > of the mount it...goes right back to where it started and the

alarm > > sounds agin.I have even slewed by hand (after waiting 30 minutes)

to > > the eastern side of the mount and then perform a goto

> command ...and

> > it still does not flip. It slews all the way back to to the

other > > side of the mount where its limit had been reached. Am I missing

> > something here? Their is no way to get the OTA to image from the

> > eastern side of the mount unless I manually put it there.Thanks,

> > Wayne



----------------------------

#22896 Oct 27, 2004

Wayne;



When I'm in the Safety Zone with my counterweights are on the East

side, OTA past Meridian into the West hemispher. When I want to go to the

West, counterweights on the West side, to continue imaging I have to

manually drive my mount out of the Safety Zone with my Handcontroller. The

I do a GoTo to an object or star in the Western hemispher. After that GoTo

finishes I then do a second GoTo my object of interest.



My East side Safety Limit is past Meridian ~2hrs, on the West side it's

~1.5hrs past Meridian into the East. When I do the GoTo to the object of

interest it goes there but when it cosses the Safty Limit zone about 10deg

before the stopping point Gemini beeps once and changes from slew to

Centering speed. Watch your Handcontroller, eventually it'll get there.



Another trick to speed up this process is change your Centering speed

to 32x or even 64x. With hgher Centering speeds your pointing accuracy may

be off a little. This always works for me, hope it helps you too...joe :)





"May You Go Among The Imperishable Stars"



Joe Mize: jmize@...

StarFields Observatory www.cav-sfo.com

Chiefland, FL 29:24'33.4"N 82:51'37.7"W

Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

----- Original Message -----

From: "Wayne Cooper" coopersx@...>

To: Losmandy_users@yahoogroups.com>

Sent: Wednesday, October 27, 2004 12:18 PM

Subject: [Losmandy_users] Re: Meridian Flip Question









--- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...> wrote:

>

> Hi Wayne,

>

> How big is your angle between the eastern and the western limit ?

> less than 180. or more than 180. ?



More then 180. I have set both limits a little further then default

on both sides of the mount.



If you say that your imaging is nearly directly overhead than maybe

> your western and eastern limit is too short and you can not image

> therefore an object at the meridien ?



I have no problem imgaging at the meridian. But when the scope is on

the west side of the monut...imaging straight up....and almost ready

to hit the leg,etc..I want to continue imaging but can't. the reason

being it wont do a goto from the other side of the mount. After

moving the scope so that the alarm stops sounding...i enter a goto

command...the scope goes right back to where it started...ready to

hit the leg on the west side of the

mount...even after waiting a good 30 minutes..then manually slewing

the scope all the way to the east and entering another goto command.

Goes right back to almost hitting the leg on the west.



As far as what I have learned is that to get a star at the meridien

> your RA axis is horizontal. If the angle in which your RA axis is

> moving is only 170. you are missing 5. from each side of the

meridien.



Sorry. I may be misreading your solution or I may not have stated

my problem correctly. Let me know if I may not be following this

right. I think the angles that you mention may not be the cause. If

so

let me know. Sincerely, Wayne



If your angle is about 190., which should be possible, all

depends

> what is hanging on the side of the OTA, then you should have no

> problem.

>

> regards Rainer

>

>

> --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

coopersx@c...>

> wrote:

> >

> > I have a G-11/Gemini level 3.103. I have set the saftey limits

in

> > east and west.Most of my imaging is just about directly

overhead.

> > The OTA for what ever reason always slews the the extreme west

side

> > when I perform a goto command. Once the alarm rings that it has

> > reached

> > its saftey limit on the west side of the mount...I will give a

goto

> > command to the same object...but instead of moving to the other

> side

> > of the mount it...goes right back to where it started and the

alarm

> > sounds agin.I have even slewed by hand (after waiting 30 minutes)

to

> > the eastern side of the mount and then perform a goto

> command ...and

> > it still does not flip. It slews all the way back to to the

other

> > side of the mount where its limit had been reached. Am I missing

> > something here? Their is no way to get the OTA to image from the

> > eastern side of the mount unless I manually put it there.Thanks,

> > Wayne















Yahoo! Groups Links







----------------------------

#22897 Oct 27, 2004

Hi Wayne,



Sounds OK what you have as limits on East and West. I assume you also

have the limit on the eastern side a little bit lower than horizontal.



I have noticed that the Gemini slows down quite some degrees before

it hits the limit. Could that be a problem that it includes this zone

for avoiding the new position on the other side ?



30minutes are 7.5. so it should be easily out of the danger zone.



Frankly I do not understand it. I can not simulate your problem

because my G11 is standing in the studio and I can not point up to

the Zenith without hitting anything. Sorry. I would gladly try it but

space is limited.



regards Rainer



----------------------------

#22898 Oct 27, 2004

--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote: > Wayne;

>

> When I'm in the Safety Zone with my counterweights are on the

East > side, OTA past Meridian into the West hemispher. When I want to

go to the > West, counterweights on the West side, to continue imaging I have

to > manually drive my mount out of the Safety Zone with my

Handcontroller. The > I do a GoTo to an object or star in the Western hemispher. After

that GoTo > finishes I then do a second GoTo my object of interest.



***Thanks Joe. I will try this. I know I have tried selecting other

objects just to see if it would switch. I am *unsure* if theose

objects were on the west as you state. Sounds like that may work.

I'll choose an object on the west a little closer to the horizon to

be safe. Clear skies tonight and I will definetly be out there.



My East side Safety Limit is past Meridian ~2hrs, on the West

side it's > ~1.5hrs past Meridian into the East. When I do the GoTo to the

object of > interest it goes there but when it cosses the Safty Limit zone

about 10deg > before the stopping point Gemini beeps once and changes from slew

to > Centering speed. Watch your Handcontroller, eventually it'll get

there.



*** I think it has gotten passed that point. The alarm is

continuous ...not beeping



Another trick to speed up this process is change your

Centering speed > to 32x or even 64x. With hgher Centering speeds your pointing

accuracy may > be off a little. This always works for me, hope it helps you

too...joe :)



***I am not sure if this would work if the alarm is already sounding

its non-stop tone?

Thanks for your tips and all your help. I will look over the manual

again also. I thought I remember something about the Gemini giving a

read out stating how long before the object crosses the

Meridian...giving you the option to start imaging or waiting for it

to cross. Those #'s may provide more info? I hope your tips work. I

will have a hard time manually finding what I am trying to image.

Thanks, Wayne

> "May You Go Among The Imperishable Stars"

>

> Joe Mize: jmize@s...

> StarFields Observatory www.cav-sfo.com

> Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:18 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

wrote: > >

> > Hi Wayne,

> >

> > How big is your angle between the eastern and the western limit ?

> > less than 180. or more than 180. ?

>

> More then 180. I have set both limits a little further then default

> on both sides of the mount.

>

> If you say that your imaging is nearly directly overhead than

maybe > > your western and eastern limit is too short and you can not image

> > therefore an object at the meridien ?

>

> I have no problem imgaging at the meridian. But when the scope is

on > the west side of the monut...imaging straight up....and almost

ready > to hit the leg,etc..I want to continue imaging but can't. the

reason > being it wont do a goto from the other side of the mount. After

> moving the scope so that the alarm stops sounding...i enter a goto

> command...the scope goes right back to where it started...ready to

> hit the leg on the west side of the

> mount...even after waiting a good 30 minutes..then manually slewing

> the scope all the way to the east and entering another goto

command. > Goes right back to almost hitting the leg on the west.

>

> As far as what I have learned is that to get a star at the meridien

> > your RA axis is horizontal. If the angle in which your RA axis is

> > moving is only 170. you are missing 5. from each side of the

> meridien.

>

> Sorry. I may be misreading your solution or I may not have stated

> my problem correctly. Let me know if I may not be following this

> right. I think the angles that you mention may not be the cause. If

> so

> let me know. Sincerely, Wayne

>

> If your angle is about 190., which should be possible, all

> depends

> > what is hanging on the side of the OTA, then you should have no

> > problem.

> >

> > regards Rainer

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> coopersx@c...>

> > wrote:

> > >

> > > I have a G-11/Gemini level 3.103. I have set the saftey limits

> in

> > > east and west.Most of my imaging is just about directly

> overhead.

> > > The OTA for what ever reason always slews the the extreme west

> side

> > > when I perform a goto command. Once the alarm rings that it

has > > > reached

> > > its saftey limit on the west side of the mount...I will give a

> goto

> > > command to the same object...but instead of moving to the other

> > side

> > > of the mount it...goes right back to where it started and the

> alarm

> > > sounds agin.I have even slewed by hand (after waiting 30

minutes) > to

> > > the eastern side of the mount and then perform a goto

> > command ...and

> > > it still does not flip. It slews all the way back to to the

> other

> > > side of the mount where its limit had been reached. Am I

missing > > > something here? Their is no way to get the OTA to image from

the > > > eastern side of the mount unless I manually put it

there.Thanks, > > > Wayne

>

>

>

>

>

>

>

> Yahoo! Groups Links







----------------------------

#22899 Oct 27, 2004

--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote: > Wayne;

>

> When I'm in the Safety Zone with my counterweights are on the

East > side, OTA past Meridian into the West hemispher. When I want to

go to the > West, counterweights on the West side, to continue imaging I have

to > manually drive my mount out of the Safety Zone with my

Handcontroller. The > I do a GoTo to an object or star in the Western hemispher. After

that GoTo > finishes I then do a second GoTo my object of interest.



***Thanks Joe. I will try this. I know I have tried selecting other

objects just to see if it would switch. I am *unsure* if theose

objects were on the west as you state. Sounds like that may work.

I'll choose an object on the west a little closer to the horizon to

be safe. Clear skies tonight and I will definetly be out there.



My East side Safety Limit is past Meridian ~2hrs, on the West

side it's > ~1.5hrs past Meridian into the East. When I do the GoTo to the

object of > interest it goes there but when it cosses the Safty Limit zone

about 10deg > before the stopping point Gemini beeps once and changes from slew

to > Centering speed. Watch your Handcontroller, eventually it'll get

there.



*** I think it has gotten passed that point. The alarm is

continuous ...not beeping



Another trick to speed up this process is change your

Centering speed > to 32x or even 64x. With hgher Centering speeds your pointing

accuracy may > be off a little. This always works for me, hope it helps you

too...joe :)



***I am not sure if this would work if the alarm is already sounding

its non-stop tone?

Thanks for your tips and all your help. I will look over the manual

again also. I thought I remember something about the Gemini giving a

read out stating how long before the object crosses the

Meridian...giving you the option to start imaging or waiting for it

to cross. Those #'s may provide more info? I hope your tips work. I

will have a hard time manually finding what I am trying to image.

Thanks, Wayne

> "May You Go Among The Imperishable Stars"

>

> Joe Mize: jmize@s...

> StarFields Observatory www.cav-sfo.com

> Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:18 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

wrote: > >

> > Hi Wayne,

> >

> > How big is your angle between the eastern and the western limit ?

> > less than 180. or more than 180. ?

>

> More then 180. I have set both limits a little further then default

> on both sides of the mount.

>

> If you say that your imaging is nearly directly overhead than

maybe > > your western and eastern limit is too short and you can not image

> > therefore an object at the meridien ?

>

> I have no problem imgaging at the meridian. But when the scope is

on > the west side of the monut...imaging straight up....and almost

ready > to hit the leg,etc..I want to continue imaging but can't. the

reason > being it wont do a goto from the other side of the mount. After

> moving the scope so that the alarm stops sounding...i enter a goto

> command...the scope goes right back to where it started...ready to

> hit the leg on the west side of the

> mount...even after waiting a good 30 minutes..then manually slewing

> the scope all the way to the east and entering another goto

command. > Goes right back to almost hitting the leg on the west.

>

> As far as what I have learned is that to get a star at the meridien

> > your RA axis is horizontal. If the angle in which your RA axis is

> > moving is only 170. you are missing 5. from each side of the

> meridien.

>

> Sorry. I may be misreading your solution or I may not have stated

> my problem correctly. Let me know if I may not be following this

> right. I think the angles that you mention may not be the cause. If

> so

> let me know. Sincerely, Wayne

>

> If your angle is about 190., which should be possible, all

> depends

> > what is hanging on the side of the OTA, then you should have no

> > problem.

> >

> > regards Rainer

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> coopersx@c...>

> > wrote:

> > >

> > > I have a G-11/Gemini level 3.103. I have set the saftey limits

> in

> > > east and west.Most of my imaging is just about directly

> overhead.

> > > The OTA for what ever reason always slews the the extreme west

> side

> > > when I perform a goto command. Once the alarm rings that it

has > > > reached

> > > its saftey limit on the west side of the mount...I will give a

> goto

> > > command to the same object...but instead of moving to the other

> > side

> > > of the mount it...goes right back to where it started and the

> alarm

> > > sounds agin.I have even slewed by hand (after waiting 30

minutes) > to

> > > the eastern side of the mount and then perform a goto

> > command ...and

> > > it still does not flip. It slews all the way back to to the

> other

> > > side of the mount where its limit had been reached. Am I

missing > > > something here? Their is no way to get the OTA to image from

the > > > eastern side of the mount unless I manually put it

there.Thanks, > > > Wayne

>

>

>

>

>

>

>

> Yahoo! Groups Links







----------------------------

#22900 Oct 27, 2004

Hi Ranier and thanks for your advice. That was a great Idea about

the limits being to short. I should have mentioned I set the

limit's, and the scope was almost hitting the leg. If that were not

the case...your were dead on to a possible cause...that I was

unaware of untill now. thanks for your help...I am going to check a

couple of things in the manual and do some indoor testing before

setting up tonight. I hope everything works and I get a good shot

tonight. I'll post my results...hopefully this is not an issue...I

never paid it much mind, and in the past, just gave up on that

object and would manually select something else. Sincerely, Wayne



--- i

n Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...> wrote: >

> Hi Wayne,

>

> Sounds OK what you have as limits on East and West. I assume you

also > have the limit on the eastern side a little bit lower than

horizontal. >

> I have noticed that the Gemini slows down quite some degrees

before > it hits the limit. Could that be a problem that it includes this

zone > for avoiding the new position on the other side ?

>

> 30minutes are 7.5. so it should be easily out of the danger zone.

>

> Frankly I do not understand it. I can not simulate your problem

> because my G11 is standing in the studio and I can not point up to

> the Zenith without hitting anything. Sorry. I would gladly try it

but > space is limited.

>

> regards Rainer



----------------------------

#22901 Oct 27, 2004

*** I think it has gotten passed that point. The alarm is

continuous ...not beeping



***I am not sure if this would work if the alarm is already sounding

its non-stop tone?



When you're there, continous beep, Tracking has already stopped anyway.

With your Handcontroller set your Centering speed to 32x, drive it East out

of the Safety Zone, do a GoTo to something in the West, then do another GoTo

to your object. When it crosses the Western Hemispher's Safety Zone it will

change from Slew speed to Centering speed. I haven't found it made any

difference as to which object I chose for the first GoTo, so long as is

isn't in the Safety Zone covered by 'both' Safety Zone overlaps. Don't

forget to change your Centring speed back to what you usually use.



I thought I remember something about the Gemini giving a

read out stating how long before the object crosses the

Meridian...giving you the option to start imaging or waiting for it

to cross. Those #'s may provide more info?



Yea, me too. I believe its got to do something with the display which shows

the offsets before you initiate the actual GoTo. Happy Mooning...joe :)





"May You Go Among The Imperishable Stars"



Joe Mize: jmize@...

StarFields Observatory www.cav-sfo.com

Chiefland, FL 29:24'33.4"N 82:51'37.7"W

Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

----- Original Message -----

From: "Wayne Cooper" coopersx@...>

To: Losmandy_users@yahoogroups.com>

Sent: Wednesday, October 27, 2004 12:59 PM

Subject: [Losmandy_users] Re: Meridian Flip Question









--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> Wayne;

>

> When I'm in the Safety Zone with my counterweights are on the

East

> side, OTA past Meridian into the West hemispher. When I want to

go to the

> West, counterweights on the West side, to continue imaging I have

to

> manually drive my mount out of the Safety Zone with my

Handcontroller. The

> I do a GoTo to an object or star in the Western hemispher. After

that GoTo

> finishes I then do a second GoTo my object of interest.



***Thanks Joe. I will try this. I know I have tried selecting other

objects just to see if it would switch. I am *unsure* if theose

objects were on the west as you state. Sounds like that may work.

I'll choose an object on the west a little closer to the horizon to

be safe. Clear skies tonight and I will definetly be out there.



My East side Safety Limit is past Meridian ~2hrs, on the West

side it's

> ~1.5hrs past Meridian into the East. When I do the GoTo to the

object of

> interest it goes there but when it cosses the Safty Limit zone

about 10deg

> before the stopping point Gemini beeps once and changes from slew

to

> Centering speed. Watch your Handcontroller, eventually it'll get

there.



*** I think it has gotten passed that point. The alarm is

continuous ...not beeping



Another trick to speed up this process is change your

Centering speed

> to 32x or even 64x. With hgher Centering speeds your pointing

accuracy may

> be off a little. This always works for me, hope it helps you

too...joe :)



***I am not sure if this would work if the alarm is already sounding

its non-stop tone?

Thanks for your tips and all your help. I will look over the manual

again also. I thought I remember something about the Gemini giving a

read out stating how long before the object crosses the

Meridian...giving you the option to start imaging or waiting for it

to cross. Those #'s may provide more info? I hope your tips work. I

will have a hard time manually finding what I am trying to image.

Thanks, Wayne



> "May You Go Among The Imperishable Stars"

>

> Joe Mize: jmize@s...

> StarFields Observatory www.cav-sfo.com

> Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:18 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

wrote:

> >

> > Hi Wayne,

> >

> > How big is your angle between the eastern and the western limit ?

> > less than 180. or more than 180. ?

>

> More then 180. I have set both limits a little further then default

> on both sides of the mount.

>

> If you say that your imaging is nearly directly overhead than

maybe

> > your western and eastern limit is too short and you can not image

> > therefore an object at the meridien ?

>

> I have no problem imgaging at the meridian. But when the scope is

on

> the west side of the monut...imaging straight up....and almost

ready

> to hit the leg,etc..I want to continue imaging but can't. the

reason

> being it wont do a goto from the other side of the mount. After

> moving the scope so that the alarm stops sounding...i enter a goto

> command...the scope goes right back to where it started...ready to

> hit the leg on the west side of the

> mount...even after waiting a good 30 minutes..then manually slewing

> the scope all the way to the east and entering another goto

command.

> Goes right back to almost hitting the leg on the west.

>

> As far as what I have learned is that to get a star at the meridien

> > your RA axis is horizontal. If the angle in which your RA axis is

> > moving is only 170. you are missing 5. from each side of the

> meridien.

>

> Sorry. I may be misreading your solution or I may not have stated

> my problem correctly. Let me know if I may not be following this

> right. I think the angles that you mention may not be the cause. If

> so

> let me know. Sincerely, Wayne

>

> If your angle is about 190., which should be possible, all

> depends

> > what is hanging on the side of the OTA, then you should have no

> > problem.

> >

> > regards Rainer

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> coopersx@c...>

> > wrote:

> > >

> > > I have a G-11/Gemini level 3.103. I have set the saftey limits

> in

> > > east and west.Most of my imaging is just about directly

> overhead.

> > > The OTA for what ever reason always slews the the extreme west

> side

> > > when I perform a goto command. Once the alarm rings that it

has

> > > reached

> > > its saftey limit on the west side of the mount...I will give a

> goto

> > > command to the same object...but instead of moving to the other

> > side

> > > of the mount it...goes right back to where it started and the

> alarm

> > > sounds agin.I have even slewed by hand (after waiting 30

minutes)

> to

> > > the eastern side of the mount and then perform a goto

> > command ...and

> > > it still does not flip. It slews all the way back to to the

> other

> > > side of the mount where its limit had been reached. Am I

missing

> > > something here? Their is no way to get the OTA to image from

the

> > > eastern side of the mount unless I manually put it

there.Thanks,

> > > Wayne

>

>

>

>

>

>

>

> Yahoo! Groups Links















Yahoo! Groups Links







----------------------------

#22903 Oct 27, 2004

I haven't found it made any > difference as to which object I chose for the first GoTo, so long

as is > isn't in the Safety Zone covered by 'both' Safety Zone overlaps.

Don't > forget to change your Centring speed back to what you usually use.



*** Hmmm! Thanks Joe. that may be the solution...and what it is that

I am not doing. I may be selecting the first goto object that is in

the west saftey zone. I chose m31 as my first test goto last night

after selecting the object that caused the beeping

did not work. M31 was on the east side of the sky though (i thought)

and should not have interfered with the east side saftey stop

settings. I'll have to try this out a little more thoroughly

tonight...selecting my first goto toward the west...where the scope

always seems to end up.

Thanks, Wayne >

>

>

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:59 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> > Wayne;

> >

> > When I'm in the Safety Zone with my counterweights are on

the > East

> > side, OTA past Meridian into the West hemispher. When I want to

> go to the

> > West, counterweights on the West side, to continue imaging I have

> to

> > manually drive my mount out of the Safety Zone with my

> Handcontroller. The

> > I do a GoTo to an object or star in the Western hemispher. After

> that GoTo

> > finishes I then do a second GoTo my object of interest.

>

> ***Thanks Joe. I will try this. I know I have tried selecting

other > objects just to see if it would switch. I am *unsure* if theose

> objects were on the west as you state. Sounds like that may work.

> I'll choose an object on the west a little closer to the horizon to

> be safe. Clear skies tonight and I will definetly be out there.

>

> My East side Safety Limit is past Meridian ~2hrs, on the West

> side it's

> > ~1.5hrs past Meridian into the East. When I do the GoTo to the

> object of

> > interest it goes there but when it cosses the Safty Limit zone

> about 10deg

> > before the stopping point Gemini beeps once and changes from slew

> to

> > Centering speed. Watch your Handcontroller, eventually it'll get

> there.

>

> *** I think it has gotten passed that point. The alarm is

> continuous ...not beeping

>

> Another trick to speed up this process is change your

> Centering speed

> > to 32x or even 64x. With hgher Centering speeds your pointing

> accuracy may

> > be off a little. This always works for me, hope it helps you

> too...joe :)

>

> ***I am not sure if this would work if the alarm is already

sounding > its non-stop tone?

> Thanks for your tips and all your help. I will look over the

manual > again also. I thought I remember something about the Gemini giving

a > read out stating how long before the object crosses the

> Meridian...giving you the option to start imaging or waiting for it

> to cross. Those #'s may provide more info? I hope your tips work. I

> will have a hard time manually finding what I am trying to image.

> Thanks, Wayne

>

> > "May You Go Among The Imperishable Stars"

> >

> > Joe Mize: jmize@s...

> > StarFields Observatory www.cav-sfo.com

> > Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> > Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

> >

> > ----- Original Message -----

> > From: "Wayne Cooper" coopersx@c...>

> > To: Losmandy_users@yahoogroups.com>

> > Sent: Wednesday, October 27, 2004 12:18 PM

> > Subject: [Losmandy_users] Re: Meridian Flip Question

> >

> >

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

> wrote:

> > >

> > > Hi Wayne,

> > >

> > > How big is your angle between the eastern and the western

limit ? > > > less than 180. or more than 180. ?

> >

> > More then 180. I have set both limits a little further then

default > > on both sides of the mount.

> >

> > If you say that your imaging is nearly directly overhead than

> maybe

> > > your western and eastern limit is too short and you can not

image > > > therefore an object at the meridien ?

> >

> > I have no problem imgaging at the meridian. But when the scope is

> on

> > the west side of the monut...imaging straight up....and almost

> ready

> > to hit the leg,etc..I want to continue imaging but can't. the

> reason

> > being it wont do a goto from the other side of the mount. After

> > moving the scope so that the alarm stops sounding...i enter a

goto > > command...the scope goes right back to where it started...ready

to > > hit the leg on the west side of the

> > mount...even after waiting a good 30 minutes..then manually

slewing > > the scope all the way to the east and entering another goto

> command.

> > Goes right back to almost hitting the leg on the west.

> >

> > As far as what I have learned is that to get a star at the

meridien > > > your RA axis is horizontal. If the angle in which your RA axis

is > > > moving is only 170. you are missing 5. from each side of

the > > meridien.

> >

> > Sorry. I may be misreading your solution or I may not have stated

> > my problem correctly. Let me know if I may not be following this

> > right. I think the angles that you mention may not be the cause.

If > > so

> > let me know. Sincerely, Wayne

> >

> > If your angle is about 190., which should be possible, all

> > depends

> > > what is hanging on the side of the OTA, then you should have no

> > > problem.

> > >

> > > regards Rainer

> > >

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> > coopersx@c...>

> > > wrote:

> > > >

> > > > I have a G-11/Gemini level 3.103. I have set the saftey

limits > > in

> > > > east and west.Most of my imaging is just about directly

> > overhead.

> > > > The OTA for what ever reason always slews the the extreme

west > > side

> > > > when I perform a goto command. Once the alarm rings that it

> has

> > > > reached

> > > > its saftey limit on the west side of the mount...I will give

a > > goto

> > > > command to the same object...but instead of moving to the

other > > > side

> > > > of the mount it...goes right back to where it started and the

> > alarm

> > > > sounds agin.I have even slewed by hand (after waiting 30

> minutes)

> > to

> > > > the eastern side of the mount and then perform a goto

> > > command ...and

> > > > it still does not flip. It slews all the way back to to the

> > other

> > > > side of the mount where its limit had been reached. Am I

> missing

> > > > something here? Their is no way to get the OTA to image from

> the

> > > > eastern side of the mount unless I manually put it

> there.Thanks,

> > > > Wayne

> >

> >

> >

> >

> >

> >

> >

> > Yahoo! Groups Links

>

>

>

>

>

>

>

> Yahoo! Groups Links







----------------------------

#22908 Oct 28, 2004

Hi joe. Fantastic. Your suggestion worked. After reaching the saftey

stop, I chose a bright star..then selected goto. I then reselected

the object I was imaging and it went right to it...from the other

side of the mount. Thanks, Wayne :)

--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

>

> *** I think it has gotten passed that point. The alarm is

> continuous ...not beeping

>

> ***I am not sure if this would work if the alarm is already

sounding

> its non-stop tone?

>

> When you're there, continous beep, Tracking has already stopped

anyway.

> With your Handcontroller set your Centering speed to 32x, drive it

East out

> of the Safety Zone, do a GoTo to something in the West, then do

another GoTo

> to your object. When it crosses the Western Hemispher's Safety

Zone it will

> change from Slew speed to Centering speed. I haven't found it

made any

> difference as to which object I chose for the first GoTo, so long

as is

> isn't in the Safety Zone covered by 'both' Safety Zone overlaps.

Don't

> forget to change your Centring speed back to what you usually use.

>

> I thought I remember something about the Gemini giving a

> read out stating how long before the object crosses the

> Meridian...giving you the option to start imaging or waiting for it

> to cross. Those #'s may provide more info?

>

> Yea, me too. I believe its got to do something with the display

which shows

> the offsets before you initiate the actual GoTo. Happy

Mooning...joe :)

>

>

> "May You Go Among The Imperishable Stars"

>

> Joe Mize: jmize@s...

> StarFields Observatory www.cav-sfo.com

> Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:59 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> > Wayne;

> >

> > When I'm in the Safety Zone with my counterweights are on

the

> East

> > side, OTA past Meridian into the West hemispher. When I want to

> go to the

> > West, counterweights on the West side, to continue imaging I have

> to

> > manually drive my mount out of the Safety Zone with my

> Handcontroller. The

> > I do a GoTo to an object or star in the Western hemispher. After

> that GoTo

> > finishes I then do a second GoTo my object of interest.

>

> ***Thanks Joe. I will try this. I know I have tried selecting

other

> objects just to see if it would switch. I am *unsure* if theose

> objects were on the west as you state. Sounds like that may work.

> I'll choose an object on the west a little closer to the horizon to

> be safe. Clear skies tonight and I will definetly be out there.

>

> My East side Safety Limit is past Meridian ~2hrs, on the West

> side it's

> > ~1.5hrs past Meridian into the East. When I do the GoTo to the

> object of

> > interest it goes there but when it cosses the Safty Limit zone

> about 10deg

> > before the stopping point Gemini beeps once and changes from slew

> to

> > Centering speed. Watch your Handcontroller, eventually it'll get

> there.

>

> *** I think it has gotten passed that point. The alarm is

> continuous ...not beeping

>

> Another trick to speed up this process is change your

> Centering speed

> > to 32x or even 64x. With hgher Centering speeds your pointing

> accuracy may

> > be off a little. This always works for me, hope it helps you

> too...joe :)

>

> ***I am not sure if this would work if the alarm is already

sounding

> its non-stop tone?

> Thanks for your tips and all your help. I will look over the

manual

> again also. I thought I remember something about the Gemini giving

a

> read out stating how long before the object crosses the

> Meridian...giving you the option to start imaging or waiting for it

> to cross. Those #'s may provide more info? I hope your tips work. I

> will have a hard time manually finding what I am trying to image.

> Thanks, Wayne

>

> > "May You Go Among The Imperishable Stars"

> >

> > Joe Mize: jmize@s...

> > StarFields Observatory www.cav-sfo.com

> > Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> > Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

> >

> > ----- Original Message -----

> > From: "Wayne Cooper" coopersx@c...>

> > To: Losmandy_users@yahoogroups.com>

> > Sent: Wednesday, October 27, 2004 12:18 PM

> > Subject: [Losmandy_users] Re: Meridian Flip Question

> >

> >

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

> wrote:

> > >

> > > Hi Wayne,

> > >

> > > How big is your angle between the eastern and the western

limit ?

> > > less than 180. or more than 180. ?

> >

> > More then 180. I have set both limits a little further then

default

> > on both sides of the mount.

> >

> > If you say that your imaging is nearly directly overhead than

> maybe

> > > your western and eastern limit is too short and you can not

image

> > > therefore an object at the meridien ?

> >

> > I have no problem imgaging at the meridian. But when the scope is

> on

> > the west side of the monut...imaging straight up....and almost

> ready

> > to hit the leg,etc..I want to continue imaging but can't. the

> reason

> > being it wont do a goto from the other side of the mount. After

> > moving the scope so that the alarm stops sounding...i enter a

goto

> > command...the scope goes right back to where it started...ready

to

> > hit the leg on the west side of the

> > mount...even after waiting a good 30 minutes..then manually

slewing

> > the scope all the way to the east and entering another goto

> command.

> > Goes right back to almost hitting the leg on the west.

> >

> > As far as what I have learned is that to get a star at the

meridien

> > > your RA axis is horizontal. If the angle in which your RA axis

is

> > > moving is only 170. you are missing 5. from each side of

the

> > meridien.

> >

> > Sorry. I may be misreading your solution or I may not have stated

> > my problem correctly. Let me know if I may not be following this

> > right. I think the angles that you mention may not be the cause.

If

> > so

> > let me know. Sincerely, Wayne

> >

> > If your angle is about 190., which should be possible, all

> > depends

> > > what is hanging on the side of the OTA, then you should have no

> > > problem.

> > >

> > > regards Rainer

> > >

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> > coopersx@c...>

> > > wrote:

> > > >

> > > > I have a G-11/Gemini level 3.103. I have set the saftey

limits

> > in

> > > > east and west.Most of my imaging is just about directly

> > overhead.

> > > > The OTA for what ever reason always slews the the extreme

west

> > side

> > > > when I perform a goto command. Once the alarm rings that it

> has

> > > > reached

> > > > its saftey limit on the west side of the mount...I will give

a

> > goto

> > > > command to the same object...but instead of moving to the

other

> > > side

> > > > of the mount it...goes right back to where it started and the

> > alarm

> > > > sounds agin.I have even slewed by hand (after waiting 30

> minutes)

> > to

> > > > the eastern side of the mount and then perform a goto

> > > command ...and

> > > > it still does not flip. It slews all the way back to to the

> > other

> > > > side of the mount where its limit had been reached. Am I

> missing

> > > > something here? Their is no way to get the OTA to image from

> the

> > > > eastern side of the mount unless I manually put it

> there.Thanks,

> > > > Wayne

> >

> >

> >

> >

> >

> >

> >

> > Yahoo! Groups Links

>

>

>

>

>

>

>

> Yahoo! Groups Links







----------------------------

#22914 Oct 28, 2004

Wayne;



Whoopie!!! Glad it worked for you too.



I couldn't tell by your post but I manually drive my mount out of the

Safety Zone before I do the GoTo to an object in the opposite hemisphere.



It sure would be nice if the Meridian Flip would be automatic so when

in the middle of imaging an object it would flip without command and

relocate the object without owner intervention. But,,, then if it could do

that someone would want it to reacquire the guide star and continue the

image without intervention. Sheesh, if that were possible we'd never go

outside and see the wonderous sky and check for clouds. Then again there

that $500 Cloud Sensor.......... :))





"May You Go Among The Imperishable Stars"



Joe Mize: jmize@...

StarFields Observatory www.cav-sfo.com

Chiefland, FL 29:24'33.4"N 82:51'37.7"W

Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

----- Original Message -----

From: "Wayne Cooper" coopersx@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, October 28, 2004 5:08 AM

Subject: [Losmandy_users] Re: Meridian Flip Question/Thanks Joe









Hi joe. Fantastic. Your suggestion worked. After reaching the saftey

stop, I chose a bright star..then selected goto. I then reselected

the object I was imaging and it went right to it...from the other

side of the mount. Thanks, Wayne :)



--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

>

> *** I think it has gotten passed that point. The alarm is

> continuous ...not beeping

>

> ***I am not sure if this would work if the alarm is already

sounding

> its non-stop tone?

>

> When you're there, continous beep, Tracking has already stopped

anyway.

> With your Handcontroller set your Centering speed to 32x, drive it

East out

> of the Safety Zone, do a GoTo to something in the West, then do

another GoTo

> to your object. When it crosses the Western Hemispher's Safety

Zone it will

> change from Slew speed to Centering speed. I haven't found it

made any

> difference as to which object I chose for the first GoTo, so long

as is

> isn't in the Safety Zone covered by 'both' Safety Zone overlaps.

Don't

> forget to change your Centring speed back to what you usually use.

>

> I thought I remember something about the Gemini giving a

> read out stating how long before the object crosses the

> Meridian...giving you the option to start imaging or waiting for it

> to cross. Those #'s may provide more info?

>

> Yea, me too. I believe its got to do something with the display

which shows

> the offsets before you initiate the actual GoTo. Happy

Mooning...joe :)

>

>

> "May You Go Among The Imperishable Stars"

>

> Joe Mize: jmize@s...

> StarFields Observatory www.cav-sfo.com

> Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

>

> ----- Original Message -----

> From: "Wayne Cooper" coopersx@c...>

> To: Losmandy_users@yahoogroups.com>

> Sent: Wednesday, October 27, 2004 12:59 PM

> Subject: [Losmandy_users] Re: Meridian Flip Question

>

>

>

>

> --- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> > Wayne;

> >

> > When I'm in the Safety Zone with my counterweights are on

the

> East

> > side, OTA past Meridian into the West hemispher. When I want to

> go to the

> > West, counterweights on the West side, to continue imaging I have

> to

> > manually drive my mount out of the Safety Zone with my

> Handcontroller. The

> > I do a GoTo to an object or star in the Western hemispher. After

> that GoTo

> > finishes I then do a second GoTo my object of interest.

>

> ***Thanks Joe. I will try this. I know I have tried selecting

other

> objects just to see if it would switch. I am *unsure* if theose

> objects were on the west as you state. Sounds like that may work.

> I'll choose an object on the west a little closer to the horizon to

> be safe. Clear skies tonight and I will definetly be out there.

>

> My East side Safety Limit is past Meridian ~2hrs, on the West

> side it's

> > ~1.5hrs past Meridian into the East. When I do the GoTo to the

> object of

> > interest it goes there but when it cosses the Safty Limit zone

> about 10deg

> > before the stopping point Gemini beeps once and changes from slew

> to

> > Centering speed. Watch your Handcontroller, eventually it'll get

> there.

>

> *** I think it has gotten passed that point. The alarm is

> continuous ...not beeping

>

> Another trick to speed up this process is change your

> Centering speed

> > to 32x or even 64x. With hgher Centering speeds your pointing

> accuracy may

> > be off a little. This always works for me, hope it helps you

> too...joe :)

>

> ***I am not sure if this would work if the alarm is already

sounding

> its non-stop tone?

> Thanks for your tips and all your help. I will look over the

manual

> again also. I thought I remember something about the Gemini giving

a

> read out stating how long before the object crosses the

> Meridian...giving you the option to start imaging or waiting for it

> to cross. Those #'s may provide more info? I hope your tips work. I

> will have a hard time manually finding what I am trying to image.

> Thanks, Wayne

>

> > "May You Go Among The Imperishable Stars"

> >

> > Joe Mize: jmize@s...

> > StarFields Observatory www.cav-sfo.com

> > Chiefland, FL 29:24'33.4"N 82:51'37.7"W

> > Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif

> >

> > ----- Original Message -----

> > From: "Wayne Cooper" coopersx@c...>

> > To: Losmandy_users@yahoogroups.com>

> > Sent: Wednesday, October 27, 2004 12:18 PM

> > Subject: [Losmandy_users] Re: Meridian Flip Question

> >

> >

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "Rainer" rsbfoto@r...>

> wrote:

> > >

> > > Hi Wayne,

> > >

> > > How big is your angle between the eastern and the western

limit ?

> > > less than 180. or more than 180. ?

> >

> > More then 180. I have set both limits a little further then

default

> > on both sides of the mount.

> >

> > If you say that your imaging is nearly directly overhead than

> maybe

> > > your western and eastern limit is too short and you can not

image

> > > therefore an object at the meridien ?

> >

> > I have no problem imgaging at the meridian. But when the scope is

> on

> > the west side of the monut...imaging straight up....and almost

> ready

> > to hit the leg,etc..I want to continue imaging but can't. the

> reason

> > being it wont do a goto from the other side of the mount. After

> > moving the scope so that the alarm stops sounding...i enter a

goto

> > command...the scope goes right back to where it started...ready

to

> > hit the leg on the west side of the

> > mount...even after waiting a good 30 minutes..then manually

slewing

> > the scope all the way to the east and entering another goto

> command.

> > Goes right back to almost hitting the leg on the west.

> >

> > As far as what I have learned is that to get a star at the

meridien

> > > your RA axis is horizontal. If the angle in which your RA axis

is

> > > moving is only 170. you are missing 5. from each side of

the

> > meridien.

> >

> > Sorry. I may be misreading your solution or I may not have stated

> > my problem correctly. Let me know if I may not be following this

> > right. I think the angles that you mention may not be the cause.

If

> > so

> > let me know. Sincerely, Wayne

> >

> > If your angle is about 190., which should be possible, all

> > depends

> > > what is hanging on the side of the OTA, then you should have no

> > > problem.

> > >

> > > regards Rainer

> > >

> > >

> > > --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

> > coopersx@c...>

> > > wrote:

> > > >

> > > > I have a G-11/Gemini level 3.103. I have set the saftey

limits

> > in

> > > > east and west.Most of my imaging is just about directly

> > overhead.

> > > > The OTA for what ever reason always slews the the extreme

west

> > side

> > > > when I perform a goto command. Once the alarm rings that it

> has

> > > > reached

> > > > its saftey limit on the west side of the mount...I will give

a

> > goto

> > > > command to the same object...but instead of moving to the

other

> > > side

> > > > of the mount it...goes right back to where it started and the

> > alarm

> > > > sounds agin.I have even slewed by hand (after waiting 30

> minutes)

> > to

> > > > the eastern side of the mount and then perform a goto

> > > command ...and

> > > > it still does not flip. It slews all the way back to to the

> > other

> > > > side of the mount where its limit had been reached. Am I

> missing

> > > > something here? Their is no way to get the OTA to image from

> the

> > > > eastern side of the mount unless I manually put it

> there.Thanks,

> > > > Wayne

> >

> >

> >

> >

> >

> >

> >

> > Yahoo! Groups Links

>

>

>

>

>

>

>

> Yahoo! Groups Links















Yahoo! Groups Links







----------------------------

#22916 Oct 28, 2004

Hey, not so fast! after a flip, the image will be reversed! so

reacquiring the same object is only part of the problem; you shall

recquire the same field of view, look for a suitable guide star

located on the other side of the frame, and look for the best

compromise... not so easy to be written on a script...



cheers,

Paolo





--- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> Wayne;

>



> It sure would be nice if the Meridian Flip would be automatic

so when

> in the middle of imaging an object it would flip without command

and

> relocate the object without owner intervention. But,,, then if it

could do

> that someone would want it to reacquire the guide star and

continue the

> image without intervention. Sheesh, if that were possible we'd

never go

> outside and see the wonderous sky and check for clouds. Then

again there

> that $500 Cloud Sensor.......... :))

>

> ! Groups Links



----------------------------

#22918 Oct 28, 2004

Hi Paolo,



If you are A MaxIm user, there is a freeware imaging sequencing program

available that will perform a GEM flip at a specified time. It will then do

a plate solution using the astrometric engine that comes with MaxIm to

realign the object.



I have sequenced images and done automated focusing after filter changes

using the Super Stacker program I have yet to try out the GEM flip and the

plate solution. Too darn many clouds.



Regards, Marty



----- Original Message -----

From: "paologramit" p.gram@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, October 28, 2004 10:17 AM

Subject: [Losmandy_users] Re: Meridian Flip Question/Thanks Joe





>

>

> Hey, not so fast! after a flip, the image will be reversed! so

> reacquiring the same object is only part of the problem; you shall

> recquire the same field of view, look for a suitable guide star

> located on the other side of the frame, and look for the best

> compromise... not so easy to be written on a script...

>

> cheers,

> Paolo

>

>

>

> --- In Losmandy_users@yahoogroups.com, "joe" jmize@s...> wrote:

> > Wayne;

> >

>

> > It sure would be nice if the Meridian Flip would be automatic

> so when

> > in the middle of imaging an object it would flip without command

> and

> > relocate the object without owner intervention. But,,, then if it

> could do

> > that someone would want it to reacquire the guide star and

> continue the

> > image without intervention. Sheesh, if that were possible we'd

> never go

> > outside and see the wonderous sky and check for clouds. Then

> again there

> > that $500 Cloud Sensor.......... :))

> >

> > ! Groups Links

>

>

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>

>



----------------------------

#24725 Mar 15, 2005

When imaging and the Gemini is autoguiding, is it possible to

force a meridian flip. I ask because somtimes my saftey stops are

set to agrresively. I thought I remember something about changing

the time on the Gemini hand controll making it think it has reached

its limit. I may be wrong about that but their may also be other

methods. Any suggestions as to whether this is possible. Thanks,

Wayne



----------------------------

#24726 Mar 15, 2005

Hi Wayne,



Never tried setting the time forward, although conceptually it could

work.



What I usually do is select a star past the safety limit and "goto"

to it. This forces a meridian flip. Once on the other side of the

meridian, I goto to the object of interest. Gemini knows that it's

closer to the object without doing the reverse flip, and so stays on

that side of the meridian.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "Wayne Cooper" coopersx@c...>

wrote: >

> When imaging and the Gemini is autoguiding, is it possible to

> force a meridian flip. I ask because somtimes my saftey stops are

> set to agrresively. I thought I remember something about changing

> the time on the Gemini hand controll making it think it has reached

> its limit. I may be wrong about that but their may also be other

> methods. Any suggestions as to whether this is possible. Thanks,

> Wayne



----------------------------

#24728 Mar 15, 2005

Hi Paul. Great idea. Sounds good. I spent a good part of the night

trying to get the right adapters for my Tak. FS-102 to work at it's

native F/8.

I had been using the focal reducer for so long and have recently

hard mounted my CFW-8A filter wheel. Well needless to say...Tak

refuses to put a standard T-thread on any thing they make!!! Well

almost anything. So I had to rig a 1.25 nosepiece into a very long

imaging train in order to reach focus. It looks rediculous and I

probably will not get much imaging time on either side of the

meridian. Anyway I am giving it a go at M106 and the image is much

larger than I had expected(definetly what I had hoped for) over

the F/6 focal reducer. The image scale is about 1.8 with this setup

unbinned and my guide errors are about +/- 0.1. Autoguiding is

exceptional tonight and if at all posssible I may try to get some

color data for the first time. I just have to see what the scope is

going to do. It's almost dragging the ground :) just kidding>

Thanks again. Wayne



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@h...>

wrote: >

> Hi Wayne,

>

> Never tried setting the time forward, although conceptually it

could > work.

>

> What I usually do is select a star past the safety limit

and "goto" > to it. This forces a meridian flip. Once on the other side of the

> meridian, I goto to the object of interest. Gemini knows that it's

> closer to the object without doing the reverse flip, and so stays

on > that side of the meridian.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "Wayne Cooper"

coopersx@c...> > wrote:

> >

> > When imaging and the Gemini is autoguiding, is it possible to

> > force a meridian flip. I ask because somtimes my saftey stops

are > > set to agrresively. I thought I remember something about

changing > > the time on the Gemini hand controll making it think it has

reached > > its limit. I may be wrong about that but their may also be other

> > methods. Any suggestions as to whether this is possible. Thanks,

> > Wayne







----------------------------

#26447 Jul 21, 2005

Hi Mika,



I can often go a couple of hours past the meridian with an OTA on

the mount (depends on the OTA, and the DEC position of the mount).



A G11 without an OTA will still not be able to go 24 hours, due to

the saddle plate hitting the motor or the mount.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "luostarinenmika"

luostarinenmika@y...> wrote: >

> Hello people,

>

> Someone here mentioned that the Meridian Flip needs to be done

with G11 when crossing > the meridian line.

>

> Is that really the case?

>

> Based on the pictures I have seen of G11 it would appear that

the mount can go 360 > degrees (24h) in RA.

>

> Assuming if you remove the OTA from the mount can the G11 mount

itself do a full 360 > degree RA rotation ?

>

> Thanks in advance,

> Mika



----------------------------

#26448 Jul 21, 2005

Ummm, yea, I guess. The Dec motor might collide with the RA motor at some point, though..... I know the Gemini's would......



But what good is it without an OTA on it, though? Seems like overkill for a camera-only....



Take care,

Bob



-------------- Original message --------------

>

> Hello people,

>

> Someone here mentioned that the Meridian Flip needs to be done with G11 when

> crossing

> the meridian line.

>

> Is that really the case?

>

> Based on the pictures I have seen of G11 it would appear that the mount can go

> 360

> degrees (24h) in RA.

>

> Assuming if you remove the OTA from the mount can the G11 mount itself do a full

> 360

> degree RA rotation ?

>

> Thanks in advance,

> Mika

>

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>



[Non-text portions of this message have been removed]



----------------------------

#26449 Jul 21, 2005

No no, the G11 can't rotate 360. on RA, due the collision of the DEC

and the AR motors.

The aluminium motor covers are so important... because they save the

motors if you try to make a complete rotation ! ;-)





I don't understand completely the mount without the OTA... What are

you thinking to do with the mount only? For simple astrophotograpy

it's definitevely too big :-)



Regards,

Stefano



--- In Losmandy_users@yahoogroups.com, "luostarinenmika"

luostarinenmika@y...> wrote: >

> Hello people,

>

> Someone here mentioned that the Meridian Flip needs to be done with

G11 when crossing > the meridian line.

>

> Is that really the case?

>

> Based on the pictures I have seen of G11 it would appear that the

mount can go 360 > degrees (24h) in RA.

>

> Assuming if you remove the OTA from the mount can the G11 mount

itself do a full 360 > degree RA rotation ?

>

> Thanks in advance,

> Mika



----------------------------

#26464 Jul 22, 2005

Hi Mika,



The GM-8 can rotate 360. in the RA axis



Just make sure the cable does not get wound up :-))



regards Rainer



--- In Losmandy_users@yahoogroups.com, "luostarinenmika"

luostarinenmika@y...> wrote: >

> Hello people,

>

> Someone here mentioned that the Meridian Flip needs to be done with

G11 when crossing > the meridian line.

>

> Is that really the case?

>

> Based on the pictures I have seen of G11 it would appear that the

mount can go 360 > degrees (24h) in RA.

>

> Assuming if you remove the OTA from the mount can the G11 mount

itself do a full 360 > degree RA rotation ?

>

> Thanks in advance,

> Mika



----------------------------

#26485 Jul 24, 2005

Hi All,



No, I am not going to use it without the OTA. I merely wanted to know if the mount itself

would limit the rotation and if yes then how seriously.



Naturally almost any GEM mount cant do a full 360 if you install lets say long enough OTA

into it and in that case the limitation is understandable but I found it strange if the mount

alone is having these restrictions. The only reason I can think of why the rotation would be

liimited and a Flip is required are the possible internal cables inside the mount that could

get wrapped up... but even this can be eliminated with proper design.



Anyways, I still havent found a good enough mount at a reasonable price.



I am now looking in more detail to the Gemini G41 mount that are said to be much better

than G11.





Cheers,

Mika







--- In Losmandy_users@yahoogroups.com, "stefanovezzosi" stefano.vezzosi@t...>

wrote: > No no, the G11 can't rotate 360. on RA, due the collision of the DEC

> and the AR motors.

> The aluminium motor covers are so important... because they save the

> motors if you try to make a complete rotation ! ;-)

>

>

> I don't understand completely the mount without the OTA... What are

> you thinking to do with the mount only? For simple astrophotograpy

> it's definitevely too big :-)

>

> Regards,

> Stefano

>

> --- In Losmandy_users@yahoogroups.com, "luostarinenmika"

> luostarinenmika@y...> wrote:

> >

> > Hello people,

> >

> > Someone here mentioned that the Meridian Flip needs to be done with

> G11 when crossing

> > the meridian line.

> >

> > Is that really the case?

> >

> > Based on the pictures I have seen of G11 it would appear that the

> mount can go 360

> > degrees (24h) in RA.

> >

> > Assuming if you remove the OTA from the mount can the G11 mount

> itself do a full 360

> > degree RA rotation ?

> >

> > Thanks in advance,

> > Mika







----------------------------

#26488 Jul 24, 2005

Mika,

I don't have the G11 Gemini, but with the G11, the motor box for the

RA axis will bang into the mount on either side when you aim just

past the Meridian either way. Because of this it will not go

completely around 360 degrees. When you approach the Meridian from

the East, as soon as you pass the Meridian you have to swing around

and start from the other side. Because of this I usually plan my

imaging sessions so that I only work on one side of the Meridian.

All German Equatorial Mounts are this way, whether or not they are

computerized.

Jim Smith



--- In Losmandy_users@yahoogroups.com, "luostarinenmika"

luostarinenmika@y...> wrote: >

> Hi All,

>

> No, I am not going to use it without the OTA. I merely wanted to

know if the mount itself > would limit the rotation and if yes then how seriously.

>

> Naturally almost any GEM mount cant do a full 360 if you install

lets say long enough OTA > into it and in that case the limitation is understandable but I

found it strange if the mount > alone is having these restrictions. The only reason I can think of

why the rotation would be > liimited and a Flip is required are the possible internal cables

inside the mount that could > get wrapped up... but even this can be eliminated with proper

design. >

> Anyways, I still havent found a good enough mount at a reasonable

price. >

> I am now looking in more detail to the Gemini G41 mount that are

said to be much better > than G11.

>

>

> Cheers,

> Mika

>

>

>

> --- In Losmandy_users@yahoogroups.com, "stefanovezzosi"

stefano.vezzosi@t...> > wrote:

> > No no, the G11 can't rotate 360. on RA, due the collision of the

DEC > > and the AR motors.

> > The aluminium motor covers are so important... because they save

the > > motors if you try to make a complete rotation ! ;-)

> >

> >

> > I don't understand completely the mount without the OTA... What

are > > you thinking to do with the mount only? For simple astrophotograpy

> > it's definitevely too big :-)

> >

> > Regards,

> > Stefano

> >

> > --- In Losmandy_users@yahoogroups.com, "luostarinenmika"

> > luostarinenmika@y...> wrote:

> > >

> > > Hello people,

> > >

> > > Someone here mentioned that the Meridian Flip needs to be done

with > > G11 when crossing

> > > the meridian line.

> > >

> > > Is that really the case?

> > >

> > > Based on the pictures I have seen of G11 it would appear that

the > > mount can go 360

> > > degrees (24h) in RA.

> > >

> > > Assuming if you remove the OTA from the mount can the G11 mount

> > itself do a full 360

> > > degree RA rotation ?

> > >

> > > Thanks in advance,

> > > Mika



----------------------------

#26489 Jul 24, 2005

jameslexman wrote:

>Mika,

>I don't have the G11 Gemini, but with the G11, the motor box for the

>RA axis will bang into the mount on either side when you aim just

>past the Meridian either way. Because of this it will not go

>completely around 360 degrees. When you approach the Meridian from

>the East, as soon as you pass the Meridian you have to swing around

>and start from the other side. Because of this I usually plan my

>imaging sessions so that I only work on one side of the Meridian.

>All German Equatorial Mounts are this way, whether or not they are

>computerized.

>

>

>>

>>

>

>

>

>

>

>

Mika, James et all,



I regularly image up to 2 hours past the meridian with a Gemini-G-11.



Regards



Bill



--



William R. Mattil.:.www.celestial-images.com



----------------------------

#26492 Jul 25, 2005

I did not know how far you could go. I have only had my G11 for

about 3 months and the DSCs for a month. It is good to know you can

do that.

Jim Smith



--- In Losmandy_users@yahoogroups.com, "William R. Mattil"

wrmattil@i...> wrote: > jameslexman wrote:

>

> >Mika,

> >I don't have the G11 Gemini, but with the G11, the motor box for

the > >RA axis will bang into the mount on either side when you aim just

> >past the Meridian either way. Because of this it will not go

> >completely around 360 degrees. When you approach the Meridian

from > >the East, as soon as you pass the Meridian you have to swing

around > >and start from the other side. Because of this I usually plan my

> >imaging sessions so that I only work on one side of the Meridian.

> >All German Equatorial Mounts are this way, whether or not they are

> >computerized.

> >

> >

> >>

> >>

> >

> >

> >

> >

> >

> >

> Mika, James et all,

>

> I regularly image up to 2 hours past the meridian with a Gemini-G-

11. >

> Regards

>

> Bill

>

> --

>

> William R. Mattil.:.www.celestial-images.com







----------------------------

#26495 Jul 25, 2005

I have the Gemini Level 3 with an older version of the Eprom chip.

When autoguiding it will not stop at the saftey limmits. The alarm

still sounds and warns you that it is past the safety stops but the

autoguider will continue to guide. I like this because it allows me

to check on my scope/camera and I can usually continue to autoguide

past the saftey stop limit...sometimes for an hour or more. Just

have to keep an eye so the camera does not hit anything.



I now set the saftey stop on the east side of the mount high. That

way when I start to image it has already flipped and I do not have

to worry about it. Most objects that I image are high in the sky and

can be imaged from either side of the mount(regardless of time of

night), so I set the saftey stop high on one side of the

mount...instead of waiting it out.

Take care, Wayne

www.wayne-cooper.com



--- In Losmandy_users@yahoogroups.com, "luostarinenmika"

luostarinenmika@y...> wrote: >

> Hello people,

>

> Someone here mentioned that the Meridian Flip needs to be done

with G11 when crossing > the meridian line.

>

> Is that really the case?

>

> Based on the pictures I have seen of G11 it would appear that

the mount can go 360 > degrees (24h) in RA.

>

> Assuming if you remove the OTA from the mount can the G11 mount

itself do a full 360 > degree RA rotation ?

>

> Thanks in advance,

> Mika



----------------------------

#28825 Feb 11 6:17 PM

(I posted this on the Gemini group on February 7, but it drew no responses. Dates/times

are referenced to February 7.)



Background: New-ish G11/Gemini permanently mounted in an observatory. Polar

alignment is pretty good and goto's put objects near eyepiece center; with a nearby sync

objects appear dead center. Last night the mount was under the control of TheSky 6.



I was poking around Orion early in the evening; at about 21:00 EST I did a meridian flip,

putting the OTA on the east side of the mount; Alnitak had transited at 20:39. I did a goto

on Alnitak, but it came nowhere close to the star, so I manually centered the star and did

Align Telescope > Sync. After that several goto's in the vicinity of Alnitak (searching for a

guide star for the Horsehead) were right on the money. Then, suddenly, TheSky told me

that Gemini "reported" that it couldn't perform a goto. So I went back to the hand

controller and tried to goto Alnitak again. The hand controller said that the star was below

the horizon. Hmmm. Checked Setup and discovered that Gemini had zeroed out my

geographic coordinates. Re-entered, no further problems. Was this forgetting of lat/long a

fluke?



I found a likely guide star (SAO 132451) and manually guided a couple of 90-second CCD

exposures for confirmation. I noticed that I had to make quite a few corrections; this has

not been the case with the OTA on the west side of the mount; as I noted, my polar

alignment is pretty good. I keep the east side of the mount a bit heavier than the west, and

I had moved my weights upward on the shaft after the flip to maintain this bias. Ideas as

to why guiding deteriorated following the flip would be most welcome.



Finally, an issue unrelated to Gemini or TheSky 6. I've controlled both the Gemini and an

LX200 GPS fork mount with a variety of software packages running under Mac OS 9, Mac

OS X, and Win XP Pro SP2. Regardless of OS or software brand, it sometimes happens that

the telescope position shown on the computer display is a few minutes from the true

position. Last night I settled on SAO 132451, a handy mag 7.5 star for Horsehead guiding.

Goto centered the star nicely and I did a sync via TheSky (and correct-star confirmation

came from photos) yet the on-screen crosshair was about 4 arc minutes from the star.

This behaviour was consistent on a variety of test goto's; objects were centered

and sync'ed, crosshair was off. What gives? (The latter question drew some comments, but

no resolution, in the SoftBisqUser group.)



Many thanks,



David



----------------------------

#28826 Feb 11 6:42 PM

David,



Zeroing out the geo coordinates indicates some kind of a power surge,

or more likely, a temporary power loss. This can happen due to power

line fluctuation (a brownout), a loose power connector, power cord

being stepped on, bad solder connection, or insufficient power supply.



The coordinates being off in the planetarium software can be caused

by a number of things:



1. While slewing, Gemini doesn't apply the pointing model corrections

to the reported coordinates, so while slewing, the crosshair in

TheSky will be off from the real "corrected" position. This is normal.



2. Geographic location does not match between TheSky and Gemini, or

time/timezone don't match.



3. Precession is not set properly (Gemini should have Epoch of Date

or a similar selection set, sorry don't remember the exact text).



4. Somehow Gemini was set into low precision coordinates mode.

There's a serial command that forces low or high precision mode. If

set this way, the coordinates will be only approximate in TheSky.



Do you use ASCOM driver with TheSky? ASCOM driver settings dialog

gives a very detailed view into the Gemini settings, so you can check

precession, precision, and coordinate values to try to figure out

what's going on.



Regards,



-Paul





--- In Losmandy_users@yahoogroups.com, "David Illig" usenet@...>

wrote: >

> (I posted this on the Gemini group on February 7, but it drew no

responses. Dates/times > are referenced to February 7.)

>

> Background: New-ish G11/Gemini permanently mounted in an

observatory. Polar > alignment is pretty good and goto's put objects near eyepiece

center; with a nearby sync > objects appear dead center. Last night the mount was under the

control of TheSky 6. >

> I was poking around Orion early in the evening; at about 21:00 EST

I did a meridian flip, > putting the OTA on the east side of the mount; Alnitak had

transited at 20:39. I did a goto > on Alnitak, but it came nowhere close to the star, so I manually

centered the star and did > Align Telescope > Sync. After that several goto's in the vicinity

of Alnitak (searching for a > guide star for the Horsehead) were right on the money. Then,

suddenly, TheSky told me > that Gemini "reported" that it couldn't perform a goto. So I went

back to the hand > controller and tried to goto Alnitak again. The hand controller

said that the star was below > the horizon. Hmmm. Checked Setup and discovered that Gemini had

zeroed out my > geographic coordinates. Re-entered, no further problems. Was this

forgetting of lat/long a > fluke?

>

> I found a likely guide star (SAO 132451) and manually guided a

couple of 90-second CCD > exposures for confirmation. I noticed that I had to make quite a

few corrections; this has > not been the case with the OTA on the west side of the mount; as I

noted, my polar > alignment is pretty good. I keep the east side of the mount a bit

heavier than the west, and > I had moved my weights upward on the shaft after the flip to

maintain this bias. Ideas as > to why guiding deteriorated following the flip would be most

welcome. >

> Finally, an issue unrelated to Gemini or TheSky 6. I've controlled

both the Gemini and an > LX200 GPS fork mount with a variety of software packages running

under Mac OS 9, Mac > OS X, and Win XP Pro SP2. Regardless of OS or software brand, it

sometimes happens that > the telescope position shown on the computer display is a few

minutes from the true > position. Last night I settled on SAO 132451, a handy mag 7.5 star

for Horsehead guiding. > Goto centered the star nicely and I did a sync via TheSky (and

correct-star confirmation > came from photos) yet the on-screen crosshair was about 4 arc

minutes from the star. > This behaviour was consistent on a variety of test goto's; objects

were centered > and sync'ed, crosshair was off. What gives? (The latter question

drew some comments, but > no resolution, in the SoftBisqUser group.)

>

> Many thanks,

>

> David

>







----------------------------

#28827 Feb 11 7:22 PM

By the way, since the zeroing out of the coordinates happened after a

meridian flip, I tend to suspect insufficient power supply: during a

meridian flip, the mount draws the most power from the power supply,

and if the supply is not up to the task, it will lower the voltage

resulting in a Gemini reboot and the problem you are seeing.



Regards,



-Paul

--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@...> wrote:

>

> David,

>

> Zeroing out the geo coordinates indicates some kind of a power

surge,

> or more likely, a temporary power loss. This can happen due to

power

> line fluctuation (a brownout), a loose power connector, power cord

> being stepped on, bad solder connection, or insufficient power

supply.

>

> The coordinates being off in the planetarium software can be caused

> by a number of things:

>

> 1. While slewing, Gemini doesn't apply the pointing model

corrections

> to the reported coordinates, so while slewing, the crosshair in

> TheSky will be off from the real "corrected" position. This is

normal.

>

> 2. Geographic location does not match between TheSky and Gemini, or

> time/timezone don't match.

>

> 3. Precession is not set properly (Gemini should have Epoch of Date

> or a similar selection set, sorry don't remember the exact text).

>

> 4. Somehow Gemini was set into low precision coordinates mode.

> There's a serial command that forces low or high precision mode. If

> set this way, the coordinates will be only approximate in TheSky.

>

> Do you use ASCOM driver with TheSky? ASCOM driver settings dialog

> gives a very detailed view into the Gemini settings, so you can

check

> precession, precision, and coordinate values to try to figure out

> what's going on.

>

> Regards,

>

> -Paul

>

>

> --- In Losmandy_users@yahoogroups.com, "David Illig" usenet@>

> wrote:

> >

> > (I posted this on the Gemini group on February 7, but it drew no

> responses. Dates/times

> > are referenced to February 7.)

> >

> > Background: New-ish G11/Gemini permanently mounted in an

> observatory. Polar

> > alignment is pretty good and goto's put objects near eyepiece

> center; with a nearby sync

> > objects appear dead center. Last night the mount was under the

> control of TheSky 6.

> >

> > I was poking around Orion early in the evening; at about 21:00

EST

> I did a meridian flip,

> > putting the OTA on the east side of the mount; Alnitak had

> transited at 20:39. I did a goto

> > on Alnitak, but it came nowhere close to the star, so I manually

> centered the star and did

> > Align Telescope > Sync. After that several goto's in the vicinity

> of Alnitak (searching for a

> > guide star for the Horsehead) were right on the money. Then,

> suddenly, TheSky told me

> > that Gemini "reported" that it couldn't perform a goto. So I went

> back to the hand

> > controller and tried to goto Alnitak again. The hand controller

> said that the star was below

> > the horizon. Hmmm. Checked Setup and discovered that Gemini had

> zeroed out my

> > geographic coordinates. Re-entered, no further problems. Was this

> forgetting of lat/long a

> > fluke?

> >

> > I found a likely guide star (SAO 132451) and manually guided a

> couple of 90-second CCD

> > exposures for confirmation. I noticed that I had to make quite a

> few corrections; this has

> > not been the case with the OTA on the west side of the mount; as

I

> noted, my polar

> > alignment is pretty good. I keep the east side of the mount a bit

> heavier than the west, and

> > I had moved my weights upward on the shaft after the flip to

> maintain this bias. Ideas as

> > to why guiding deteriorated following the flip would be most

> welcome.

> >

> > Finally, an issue unrelated to Gemini or TheSky 6. I've

controlled

> both the Gemini and an

> > LX200 GPS fork mount with a variety of software packages running

> under Mac OS 9, Mac

> > OS X, and Win XP Pro SP2. Regardless of OS or software brand, it

> sometimes happens that

> > the telescope position shown on the computer display is a few

> minutes from the true

> > position. Last night I settled on SAO 132451, a handy mag 7.5

star

> for Horsehead guiding.

> > Goto centered the star nicely and I did a sync via TheSky (and

> correct-star confirmation

> > came from photos) yet the on-screen crosshair was about 4 arc

> minutes from the star.

> > This behaviour was consistent on a variety of test goto's;

objects

> were centered

> > and sync'ed, crosshair was off. What gives? (The latter question

> drew some comments, but

> > no resolution, in the SoftBisqUser group.)

> >

> > Many thanks,

> >

> > David

> >

>







----------------------------

#28834 Feb 12 10:02 AM

David, strange happenings indeed. The first thing that comes to mins is

have you repleace the Gemini internal batter recentlky, CR2032(?). A weak

battery will cause many different odd things to happen...joe :)





"May You Go Among The Imperishable Stars"



Joe Mize: jmize@...

StarFields Observatory www.cav-sfo.com

Chiefland, FL 29:24'33.4"N 82:51'37.7"W

Moon Phase: tycho.usno.navy.mil/cgi-bin/phase.gif ----- Original Message -----

From: "David Illig" usenet@...>

To: Losmandy_users@yahoogroups.com>

Sent: Saturday, February 11, 2006 9:17 PM

Subject: [Losmandy_users] G-11 Meridian Flip & Other Issues





> (I posted this on the Gemini group on February 7, but it drew no

> responses. Dates/times

> are referenced to February 7.)

>

> Background: New-ish G11/Gemini permanently mounted in an observatory.

> Polar

> alignment is pretty good and goto's put objects near eyepiece center; with

> a nearby sync

> objects appear dead center. Last night the mount was under the control of

> TheSky 6.

>

> I was poking around Orion early in the evening; at about 21:00 EST I did a

> meridian flip,

> putting the OTA on the east side of the mount; Alnitak had transited at

> 20:39. I did a goto

> on Alnitak, but it came nowhere close to the star, so I manually centered

> the star and did

> Align Telescope > Sync. After that several goto's in the vicinity of

> Alnitak (searching for a

> guide star for the Horsehead) were right on the money. Then, suddenly,

> TheSky told me

> that Gemini "reported" that it couldn't perform a goto. So I went back to

> the hand

> controller and tried to goto Alnitak again. The hand controller said that

> the star was below

> the horizon. Hmmm. Checked Setup and discovered that Gemini had zeroed out

> my

> geographic coordinates. Re-entered, no further problems. Was this

> forgetting of lat/long a

> fluke?

>

> I found a likely guide star (SAO 132451) and manually guided a couple of

> 90-second CCD

> exposures for confirmation. I noticed that I had to make quite a few

> corrections; this has

> not been the case with the OTA on the west side of the mount; as I noted,

> my polar

> alignment is pretty good. I keep the east side of the mount a bit heavier

> than the west, and

> I had moved my weights upward on the shaft after the flip to maintain this

> bias. Ideas as

> to why guiding deteriorated following the flip would be most welcome.

>

> Finally, an issue unrelated to Gemini or TheSky 6. I've controlled both

> the Gemini and an

> LX200 GPS fork mount with a variety of software packages running under Mac

> OS 9, Mac

> OS X, and Win XP Pro SP2. Regardless of OS or software brand, it sometimes

> happens that

> the telescope position shown on the computer display is a few minutes from

> the true

> position. Last night I settled on SAO 132451, a handy mag 7.5 star for

> Horsehead guiding.

> Goto centered the star nicely and I did a sync via TheSky (and

> correct-star confirmation

> came from photos) yet the on-screen crosshair was about 4 arc minutes from

> the star.

> This behaviour was consistent on a variety of test goto's; objects were

> centered

> and sync'ed, crosshair was off. What gives? (The latter question drew some

> comments, but

> no resolution, in the SoftBisqUser group.)

>

> Many thanks,

>

> David

>

>

>

>

>

>

>

> Yahoo! Groups Links

>

>

>

>

>

>

>



----------------------------

#28839 Feb 12 3:07 PM

Paul K wrote:

> By the way, since the zeroing out of the coordinates happened after a

> meridian flip, I tend to suspect insufficient power supply: during a

> meridian flip, the mount draws the most power from the power supply...



I appreciate both of your replies and Joe Mize's reply as well. Due to the weather (18+" of

snow overnight) it will be a while before I'm able to get into the observatory again and look at

the issues you raised. I'm especially interested in the failure of TheSky to accurately show

telescope pointing.



The zeroing out of coordinates will be filed under "fluke" if it doesn't repeat. I'm fairly certain

the power supply is adequate; I have a BK Precision 18VDC 5A supply that seems never to be

taxed according to the digital readout.



Thanks,



David



----------------------------

#32116 Feb 11 12:53 AM

Hello group ,

cause is the first time i use GEM can anyone explain to me how to do

correct meridian flip with G11 anGemini level 3?



Thanks in advance

Nikos



----------------------------

#32118 Feb 11 9:40 AM

Hello Niko,



Kalispera.



A meridian flip happens automatically when you tell Gemini to GOTO an object

that on the other side of the meridian from where the telescope is currently

pointing. For example at 20 hours Athens time if you are looking at an

object east of the meridian such as Castor, and then tell Gemini, using the

Gemini hand controller commands, to GOTO an object, such as M31, west of the

meridian, the mount will slew to M31 and do a meridian flip in the process.



This also occurs if you are initiating a GOTO using a computer connected to

Gemini. The GOTO command does not have to come from the hand controller.



There is an area of ambiguity centered around the meridian where some

objects can be observed with the mount on either side of the meridian. If,

for example, you are trying to image an object that is still east of the

meridian, but close to the meridian and within this area of ambiguity, you

can GOTO an object far enough west of the meridian to cause the meridian

flip to occur and then GOTO the object you wish to image. Gemini will be

smart enough to keep the G11 on the west side. This will allow tracking for

image acquisition purposes to be done without having to interrupt your

imaging because of hitting the pre-set limits. This discussion depends on

how you have your Gemini limits set (see the instructions on setting slew

limits).



I hope this helped. Please ask more questions. We are here to help.



Clear skies to you,



Gary

North Chatham NY USA.



> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com]On Behalf Of ..... ........

> Sent: Sunday, February 11, 2007 3:54 AM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] MERIDIAN FLIP?????

>

>

> Hello group ,

> cause is the first time i use GEM can anyone explain to me how to do

> correct meridian flip with G11 anGemini level 3?

>

> Thanks in advance

> Nikos

>

>

>

>

> Yahoo! Groups Links

>

>

>

>







----------------------------

#32119 Feb 11 10:09 AM

Kalispera Gary

thanks a lot for you answer , my problem was it mostly for imaging session, so now it is clear to me...

When i set slew limitthis is for both sides or for just the one?



Thanks



Gary Ferdinand alaparos@...> ......:

Hello Niko,



Kalispera.



A meridian flip happens automatically when you tell Gemini to GOTO an object

that on the other side of the meridian from where the telescope is currently

pointing. For example at 20 hours Athens time if you are looking at an

object east of the meridian such as Castor, and then tell Gemini, using the

Gemini hand controller commands, to GOTO an object, such as M31, west of the

meridian, the mount will slew to M31 and do a meridian flip in the process.



This also occurs if you are initiating a GOTO using a computer connected to

Gemini. The GOTO command does not have to come from the hand controller.



There is an area of ambiguity centered around the meridian where some

objects can be observed with the mount on either side of the meridian. If,

for example, you are trying to image an object that is still east of the

meridian, but close to the meridian and within this area of ambiguity, you

can GOTO an object far enough west of the meridian to cause the meridian

flip to occur and then GOTO the object you wish to image. Gemini will be

smart enough to keep the G11 on the west side. This will allow tracking for

image acquisition purposes to be done without having to interrupt your

imaging because of hitting the pre-set limits. This discussion depends on

how you have your Gemini limits set (see the instructions on setting slew

limits).



I hope this helped. Please ask more questions. We are here to help.



Clear skies to you,



Gary

North Chatham NY USA.

> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com]On Behalf Of ..... ........

> Sent: Sunday, February 11, 2007 3:54 AM

> To: Losmandy_users@yahoogroups.com

> Subject: [Losmandy_users] MERIDIAN FLIP?????

>

>

> Hello group ,

> cause is the first time i use GEM can anyone explain to me how to do

> correct meridian flip with G11 anGemini level 3?

>

> Thanks in advance

> Nikos

>

>

>

>

> Yahoo! Groups Links

>

>

>

>













Nikos Paschalis

Nunki observatory - Skiathos

www.freewebs.com/paschalis





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----------------------------

#32120 Feb 11 10:58 AM

Each side can be set independently.



Cheers,

Paul Sterngold



--- Nikos Paschalis np252003@...> wrote:

> Kalispera Gary

> thanks a lot for you answer , my problem was it mostly for imaging session,

> so now it is clear to me...

> When i set slew limitthis is for both sides or for just the one?

>

> Thanks

>

> Gary Ferdinand alaparos@...> ......:

> Hello Niko,

>

> Kalispera.

>

> A meridian flip happens automatically when you tell Gemini to GOTO an object

> that on the other side of the meridian from where the telescope is currently

> pointing. For example at 20 hours Athens time if you are looking at an

> object east of the meridian such as Castor, and then tell Gemini, using the

> Gemini hand controller commands, to GOTO an object, such as M31, west of the

> meridian, the mount will slew to M31 and do a meridian flip in the process.

>

> This also occurs if you are initiating a GOTO using a computer connected to

> Gemini. The GOTO command does not have to come from the hand controller.

>

> There is an area of ambiguity centered around the meridian where some

> objects can be observed with the mount on either side of the meridian. If,

> for example, you are trying to image an object that is still east of the

> meridian, but close to the meridian and within this area of ambiguity, you

> can GOTO an object far enough west of the meridian to cause the meridian

> flip to occur and then GOTO the object you wish to image. Gemini will be

> smart enough to keep the G11 on the west side. This will allow tracking for

> image acquisition purposes to be done without having to interrupt your

> imaging because of hitting the pre-set limits. This discussion depends on

> how you have your Gemini limits set (see the instructions on setting slew

> limits).

>

> I hope this helped. Please ask more questions. We are here to help.

>

> Clear skies to you,

>

> Gary

> North Chatham NY USA.

>

> > -----Original Message-----

> > From: Losmandy_users@yahoogroups.com

> > [mailto:Losmandy_users@yahoogroups.com]On Behalf Of ..... ........

> > Sent: Sunday, February 11, 2007 3:54 AM

> > To: Losmandy_users@yahoogroups.com

> > Subject: [Losmandy_users] MERIDIAN FLIP?????

> >

> >

> > Hello group ,

> > cause is the first time i use GEM can anyone explain to me how to do

> > correct meridian flip with G11 anGemini level 3?

> >

> > Thanks in advance

> > Nikos

> >

> >

> >

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

>

>

>

>

>

>

> Nikos Paschalis

> Nunki observatory - Skiathos

> www.freewebs.com/paschalis

>

> ..

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> [Non-text portions of this message have been removed]

>

>

>

>

> Yahoo! Groups Links

>

>

>

>









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#32121 Feb 11 10:57 AM

--- Gary Ferdinand alaparos@...> wrote: > A meridian flip happens automatically when you tell Gemini to GOTO an object

> that on the other side of the meridian from where the telescope is currently



You can also manually initiate a meridian flip from the QuickMenu.



Cheers,

Paul Sterngold







---------------

Bored stiff? Loosen up...

Download and play hundreds of games for free on Yahoo! Games.

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----------------------------

#32122 Feb 11 11:51 AM

Thanks for jumping in, Paul. I wasn't sure of that. I've been using Gemini

level 4 and don't recall any more what level 3 (which Nikos is using) did

not have in it. CS.



Gary





> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com]On Behalf Of Paul Sterngold

> Sent: Sunday, February 11, 2007 1:58 PM

> To: Losmandy_users@yahoogroups.com

> Subject: RE: [Losmandy_users] MERIDIAN FLIP?????

>

>

> --- Gary Ferdinand alaparos@...> wrote:

> > A meridian flip happens automatically when you tell Gemini to

> GOTO an object

> > that on the other side of the meridian from where the telescope

> is currently

>

> You can also manually initiate a meridian flip from the QuickMenu.

>

> Cheers,

> Paul Sterngold

>

>

>

---------------

> __________________

> Bored stiff? Loosen up...

> Download and play hundreds of games for free on Yahoo! Games.

> games.yahoo.com/games/front

>

>

>

> Yahoo! Groups Links

>

>

>

>



----------------------------

#32123 Feb 11 12:24 PM

...But i could find it in the quick menu , the last command was "set home position"



Gary Ferdinand alaparos@...> ......: Thanks for jumping in, Paul. I wasn't sure of that. I've been using Gemini

level 4 and don't recall any more what level 3 (which Nikos is using) did

not have in it. CS.



Gary

> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

> [mailto:Losmandy_users@yahoogroups.com]On Behalf Of Paul Sterngold

> Sent: Sunday, February 11, 2007 1:58 PM

> To: Losmandy_users@yahoogroups.com

> Subject: RE: [Losmandy_users] MERIDIAN FLIP?????

>

>

> --- Gary Ferdinand alaparos@...> wrote:

> > A meridian flip happens automatically when you tell Gemini to

> GOTO an object

> > that on the other side of the meridian from where the telescope

> is currently

>

> You can also manually initiate a meridian flip from the QuickMenu.

>

> Cheers,

> Paul Sterngold

>

>

>

---------------

> __________________

> Bored stiff? Loosen up...

> Download and play hundreds of games for free on Yahoo! Games.

> games.yahoo.com/games/front

>

>

>

> Yahoo! Groups Links

>

>

>

>













Nikos Paschalis

Nunki observatory - Skiathos

www.freewebs.com/paschalis





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----------------------------

#32126 Feb 11 3:31 PM

--- Nikos Paschalis np252003@...> wrote: > ...But i could [not?] find it in the quick menu , the last command was "set

> home position"



Okay, somebody must be playing a practical joke on me. I am certain that three

nights ago, while testing out my GM8-Gemini, I saw and even used a Meridian

Flip function from the QuickMenu. Now I can not get it to show up. I tried

doing a simulated alignment procedure (in my garage), then slewed the mount to

an imaginary object near the meridian with the telescope on the west side of

the mount all the way to its limit. I then checked the QuickMenu, but there was

no Meridian Flip option. I tried several other scenarios as well, but the

option never reappeared. And there's no mention of it in the manual.



Am I dreaming? I'd better get our water tested, there must be something in

it...



Cheers,

Paul Sterngold







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----------------------------

#37418 Apr 30, 2008

Recent discussions about counterweights and the meridian flip prompted

me to take some pictures of my telescope/G-11 to illustrate various

positions and movements. Hopefully folks accustomed to fork amounts

will find these photos helpful. Here is a link to the page on my Web site:

astronomy.mdodd.com/gem_movement.html>



Enjoy.



Mike

-----



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com







----------------------------

#37421 May 1, 2008

Interestingly Ovision has a spacer that thrusts the dec axis out

further from the RA body. Looks very interesting. don't know the

price. regards greg n

--- In Losmandy_users@yahoogroups.com, "Mike Dodd" mike@...> wrote:

>

> Recent discussions about counterweights and the meridian flip prompted

> me to take some pictures of my telescope/G-11 to illustrate various

> positions and movements. Hopefully folks accustomed to fork amounts

> will find these photos helpful. Here is a link to the page on my Web

site:

> astronomy.mdodd.com/gem_movement.html>

>

> Enjoy.

>

> Mike

> -----

>

> Mike Dodd

> Montpelier, VA USA

> astronomy.mdodd.com

>



----------------------------

#37784 Jun 3, 2008

Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian flip

when the target crosses the Meridian?



Bryan

Denver



----------------------------

#37785 Jun 3, 2008

No.



Slews and goto's slow down when they get close to the safety limit

past the meridian, and eventually stop. Tracking stops when the safety

limit is exceeded. You'll have to perform a meridian flip from the

hand controller or from the PC should you want one.



Regards,



-Paul



--- In Losmandy_users@yahoogroups.com, "fraighttrain30"

bryan.wilburn@...> wrote: >

> Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian flip

> when the target crosses the Meridian?

>

> Bryan

> Denver

>



----------------------------

#37792 Jun 4, 2008

Appreciate the input, the impetus of the question is a discussion on

various mounts in a class on Beginner Astrophotography I'm giving.

The GM-8/11 are included as they are two of the better mounts

available for the novice at very reasonable prices in their payload

categories.



The Celestron CGE does an uncommented Meridian flip when the target

crosses that imaginary line in the sky. Since most folks image 1 . 1

. hours before meridian crossing to 1 . 1 . hours after a flip in the

middle is a real pain.



I generally go weights high and track across the Meridian on the

target if I have a choice. My concern was if the Gemini does the

same action as the CGE or does it allow you to track a target across

the Meridian without any antics.



Bryan

Denver



--- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@...> wrote:

>

> No.

>

> Slews and goto's slow down when they get close to the safety limit

> past the meridian, and eventually stop. Tracking stops when the

safety

> limit is exceeded. You'll have to perform a meridian flip from the

> hand controller or from the PC should you want one.

>

> Regards,

>

> -Paul

>

> --- In Losmandy_users@yahoogroups.com, "fraighttrain30"

> bryan.wilburn@> wrote:

> >

> > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

flip

> > when the target crosses the Meridian?

> >

> > Bryan

> > Denver

> >

>



----------------------------

#37797 Jun 4, 2008

Well, yes and no. It depends where you have set both the east and west limits

(see Manual section 3.3.3.); and the GoTo limit (Manual section 3.3.4).



Setting the east and west limits will depend on whether you are in the northern

or southern hemisphere, as the side of the RA motor will be opposite. Generally,

if you can go to an object without entering the safety limits, the Gemini will

not do a meridian flip.



There are two major problems with this: First, you may be able to just slew

there but your exposure length will lead to the mount tracking into the limits.

Once in the limits, the mount is stuck. While this prevents damage to the motors

and mount it is a major problem for an extended exposure.



To get around getting stuck in the safety limits, the Gemini has a "GoTo limit",

which will initiate a meridian flip *before* reaching the safety limit, so there

is enough time for an exposure before the next slew. Obviously you set the GoTo

limit to cause a meridian flip well before the safety limit is reached, so the

length of the exposure does not lead the mount to continuing tracking while

exposing, and get stuck in the safety limit.



In theory, this sounds fine. In practice, it is a major pain in the bum. It

might be alright if you are a pretty picture imager doing one exposure near the

meridian. However, if you are a scientific imager tracking an object all night

with repeated slews, multiple filter exposures and auto-focusing, it can lead to

the mount becoming stuck in the safety zone and the loss of not just one image,

but half a night's images.



Let me give an example of the above. You have scripted operation for B, V, R, I

filter exposures of an object to which you continually slew after each *set* of

filter exposures. In addition, you have scripted auto-focusing every 30 minutes.

You might set a reasonable interval so that the GoTo limit theoretically forces

a meridian flip after a set of 1-2 minute B,V,R, I exposures. But just when you

get to the critical point where a meridian flip is needed, the script starts an

autofocus and does not slew causing a meridian flip. So the mount tracks into

the safety zone while autofocusing. The result? The mount will no longer move

without physical intervention and the second half of your night's scripted

images are lost.



- Greg













-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com] On

Behalf Of fraighttrain30

Sent: Wednesday, 4 June 2008 12:33 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Gemini and Meridian flip?



Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian flip

when the target crosses the Meridian?



Bryan

Denver







---------------



Yahoo! Groups Links







----------------------------

#37798 Jun 4, 2008

I can do 2-3 hours on each side of the Meridian without flipping. No

problems with long sessions. I do a flip before imaging if I can

though, so that is will always face West. But if the object is not

already past Meridian, then this is not possible and I just image with

the weight to the East until I run out of travel, which is at least 4

hours, my normal exposure time for an object.

Floyd

--- In Losmandy_users@yahoogroups.com, "fraighttrain30"

bryan.wilburn@...> wrote: >

> Appreciate the input, the impetus of the question is a discussion on

> various mounts in a class on Beginner Astrophotography I'm giving.

> The GM-8/11 are included as they are two of the better mounts

> available for the novice at very reasonable prices in their payload

> categories.

>

> The Celestron CGE does an uncommented Meridian flip when the target

> crosses that imaginary line in the sky. Since most folks image 1 . 1

> . hours before meridian crossing to 1 . 1 . hours after a flip in the

> middle is a real pain.

>

> I generally go weights high and track across the Meridian on the

> target if I have a choice. My concern was if the Gemini does the

> same action as the CGE or does it allow you to track a target across

> the Meridian without any antics.

>

> Bryan

> Denver

>

>

> --- In Losmandy_users@yahoogroups.com, "Paul K" pkane2001@> wrote:

> >

> > No.

> >

> > Slews and goto's slow down when they get close to the safety limit

> > past the meridian, and eventually stop. Tracking stops when the

> safety

> > limit is exceeded. You'll have to perform a meridian flip from the

> > hand controller or from the PC should you want one.

> >

> > Regards,

> >

> > -Paul

> >

> > --- In Losmandy_users@yahoogroups.com, "fraighttrain30"

> > bryan.wilburn@> wrote:

> > >

> > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> flip

> > > when the target crosses the Meridian?

> > >

> > > Bryan

> > > Denver

> > >

> >

>



----------------------------

#37799 Jun 4, 2008

fraighttrain30 wrote: > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian flip

> when the target crosses the Meridian?



If you request a GOTO to a target on the other side of the meridian, the

mount will do a flip to reach that target. However, it will not flip

while TRACKING. It will track up to the safety limit, and stop.



Mike

-----



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#37802 Jun 4, 2008

Thanks for the input and info. It appears the Gemini is a bit more

on the more intelligent side and is a tad more flexible. With the

problems that could entail.



But I must admit when the CGE I borrowed flipped mid guide, I utter a

few rude words.



I'm also vey happy with my GM-8 & DSC. I can get the target well

within the FOV on a 40mm eye piece everytime.



Bryan

Denver

--- In Losmandy_users@yahoogroups.com, Mike Dodd mike@...> wrote:

>

> fraighttrain30 wrote:

> > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

flip

> > when the target crosses the Meridian?

>

> If you request a GOTO to a target on the other side of the

meridian, the

> mount will do a flip to reach that target. However, it will not

flip

> while TRACKING. It will track up to the safety limit, and stop.

>

> Mike

> -----

>

> Mike Dodd

> Montpelier, VA USA

> astronomy.mdodd.com

>



----------------------------

#37805 Jun 5, 2008

Appreciate the input, the impetus of the question is a discussion on

> various mounts in a class on Beginner Astrophotography I'm giving.

> The GM-8/11 are included as they are two of the better mounts

> available for the novice at very reasonable prices in their payload

> categories.

>

> The Celestron CGE does an uncommented Meridian flip when the target

> crosses that imaginary line in the sky. Since most folks image 1 . 1

> . hours before meridian crossing to 1 . 1 . hours after a flip in the

> middle is a real pain.

>

> I generally go weights high and track across the Meridian on the

> target if I have a choice. My concern was if the Gemini does the

> same action as the CGE or does it allow you to track a target across

> the Meridian without any antics.

>

> Bryan

> Denver

The Gemini, allows you to specify 'limits' where it will stop tracking

relative to the meridian. So you can say (for instance), that your mount

can go one hour 'beyond' the meridian. You can then start aiming at a

target 45 minutes 'east' of the meridian, but the scope positioned as if

you are on the west side of the meridian, and track right through, and

keep going. Alternatively, you can start on the same star, but with the

scope positioned for normal 'east' tracking, and the mount will pass the

meridian, but stop, when it reaches the programmed limit. It will start

a 'beep' warning, some time before the limit is reached.

It _will_ automatically flip, if you perform a 'goto' operation, to a

star that cannot be reached (within the programmed limits), with the

tube on the current side of the mount. Have a look at section 3.3.3, in

the Gemini manual, for details of the default limits, and how these can

be changed. There is also a separate (new) command, that allows you to

set a different point for the 'goto' meridian flip, from the limits, so

that the system tends to default to placing the scope, so that it can

track through the meridian without having to stop.

It is one of the best setup systems for handling the meridian around.



Best Wishes







----------------------------

#37806 Jun 5, 2008

fraighttrain30 wrote: > Thanks for the input and info. It appears the Gemini is a bit more

> on the more intelligent side and is a tad more flexible. With the

> problems that could entail.

>

> But I must admit when the CGE I borrowed flipped mid guide, I utter a

> few rude words.



I don't know what you saw, but the CGE handles the flip the same way as

the G-11/Gemini -- I checked with the Celestron CGE firmware developer,

and he verified this: "It only flips on a GOTO. It'll just stop

tracking if you let it hit the meridian while tracking or guiding."



The mount won't flip automatically, but you can buy automation software

such as ACP acp4.dc3.com/index2.html> that will detect an

upcoming transit, stop imaging, wait for the transit to occur, command

the mount to goto the target on the west side, then plate solve to

accurately center the target on the CCD chip.







Mike

-----



Mike Dodd

Montpelier, VA USA

astronomy.mdodd.com



----------------------------

#37807 Jun 5, 2008

I think the CGE was designed to flip at meridian as a matter of

choice. The Paramount ME also flips at meridian. I used to think it

got you exactly back to where you where before the flip but I think I

heard someone say that the flip even on a Paramount, is not more

accurate than about twenty arc minutes.



Ovision in France in addition to making the worm upgrade also makes a

thick metal ring that pushes the entire dec axis out further and thus

modifies the G11 to allow 180 degree tracking from one part of the

horizon to the other. I'm not sure how that works with one's RA shaft

and all of that, seesm to me you'd need a longer RA shaft, but the

modification is available.



regards

Greg N





--- In Losmandy_users@yahoogroups.com, "fraighttrain30"

bryan.wilburn@...> wrote: >

> Thanks for the input and info. It appears the Gemini is a bit more

> on the more intelligent side and is a tad more flexible. With the

> problems that could entail.

>

> But I must admit when the CGE I borrowed flipped mid guide, I utter a

> few rude words.

>

> I'm also vey happy with my GM-8 & DSC. I can get the target well

> within the FOV on a 40mm eye piece everytime.

>

> Bryan

> Denver

>

> --- In Losmandy_users@yahoogroups.com, Mike Dodd mike@> wrote:

> >

> > fraighttrain30 wrote:

> > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> flip

> > > when the target crosses the Meridian?

> >

> > If you request a GOTO to a target on the other side of the

> meridian, the

> > mount will do a flip to reach that target. However, it will not

> flip

> > while TRACKING. It will track up to the safety limit, and stop.

> >

> > Mike

> > -----

> >

> > Mike Dodd

> > Montpelier, VA USA

> > astronomy.mdodd.com

> >

>



----------------------------

#37808 Jun 5, 2008

You know I'm looking at the AP Mach 1 mount which is being sold as 7

arc seconds peak to valley for $6,000. By the time you get

counterweights and a tripod you're looking at $7,500. By contrast a

G11 with an excellent tripod (though I prefer the Berlebach) and a

counterweight thrown in, with a paddle that includes modeling of

pointing inaccuracies, is $3300. If the Ovision worm works and gets

PE down to 5 arc seconds or less peak to valley then in effect there

is no reason to buy a Mach 1. For $4k you'd get equivalent tracking

and a paddle with superior pointing accuracy.



regards

Greg N





--- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> I think the CGE was designed to flip at meridian as a matter of

> choice. The Paramount ME also flips at meridian. I used to think it

> got you exactly back to where you where before the flip but I think I

> heard someone say that the flip even on a Paramount, is not more

> accurate than about twenty arc minutes.

>

> Ovision in France in addition to making the worm upgrade also makes a

> thick metal ring that pushes the entire dec axis out further and thus

> modifies the G11 to allow 180 degree tracking from one part of the

> horizon to the other. I'm not sure how that works with one's RA shaft

> and all of that, seesm to me you'd need a longer RA shaft, but the

> modification is available.

>

> regards

> Greg N

>

>

> --- In Losmandy_users@yahoogroups.com, "fraighttrain30"

> bryan.wilburn@> wrote:

> >

> > Thanks for the input and info. It appears the Gemini is a bit more

> > on the more intelligent side and is a tad more flexible. With the

> > problems that could entail.

> >

> > But I must admit when the CGE I borrowed flipped mid guide, I utter a

> > few rude words.

> >

> > I'm also vey happy with my GM-8 & DSC. I can get the target well

> > within the FOV on a 40mm eye piece everytime.

> >

> > Bryan

> > Denver

> >

> > --- In Losmandy_users@yahoogroups.com, Mike Dodd mike@> wrote:

> > >

> > > fraighttrain30 wrote:

> > > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> > flip

> > > > when the target crosses the Meridian?

> > >

> > > If you request a GOTO to a target on the other side of the

> > meridian, the

> > > mount will do a flip to reach that target. However, it will not

> > flip

> > > while TRACKING. It will track up to the safety limit, and stop.

> > >

> > > Mike

> > > -----

> > >

> > > Mike Dodd

> > > Montpelier, VA USA

> > > astronomy.mdodd.com

> > >

> >

>







----------------------------

#37810 Jun 5, 2008

Hi Greg,

I have been down the same road, in effect, the GTO offers less payload

too. The motors and gear boxes used as well as the worms and worm

gears are of higher quality in the AP, no doubt about that. The gears

are lapped at the factory and PE is mapped and corrected, which is

very nice.

I have not actually measured the PE on my G-11, just the guiding

graphs. I do get the PE or Guiding Graph down to 1-3" peak to valley,

with maximum movements of about .25" according to PEAS and PHDAnalyser

software. This results in good photos for me, but it would be nice to

have an even better PE.

I am still waiting for the results to be published by those who have

purchased the new Ovision worm, should be interesting.

But, the additional cost of the AP covers buying a scope and camera

when added to the G-11, which is a big step in getting into

astrophotography. :^)

Floyd --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@...> wrote:

>

> You know I'm looking at the AP Mach 1 mount which is being sold as 7

> arc seconds peak to valley for $6,000. By the time you get

> counterweights and a tripod you're looking at $7,500. By contrast a

> G11 with an excellent tripod (though I prefer the Berlebach) and a

> counterweight thrown in, with a paddle that includes modeling of

> pointing inaccuracies, is $3300. If the Ovision worm works and gets

> PE down to 5 arc seconds or less peak to valley then in effect there

> is no reason to buy a Mach 1. For $4k you'd get equivalent tracking

> and a paddle with superior pointing accuracy.

>

> regards

> Greg N

>

>

>

> --- In Losmandy_users@yahoogroups.com, "gnowellsct" tim71pos@> wrote:

> >

> > I think the CGE was designed to flip at meridian as a matter of

> > choice. The Paramount ME also flips at meridian. I used to think it

> > got you exactly back to where you where before the flip but I think I

> > heard someone say that the flip even on a Paramount, is not more

> > accurate than about twenty arc minutes.

> >

> > Ovision in France in addition to making the worm upgrade also makes a

> > thick metal ring that pushes the entire dec axis out further and thus

> > modifies the G11 to allow 180 degree tracking from one part of the

> > horizon to the other. I'm not sure how that works with one's RA shaft

> > and all of that, seesm to me you'd need a longer RA shaft, but the

> > modification is available.

> >

> > regards

> > Greg N

> >

> >

> > --- In Losmandy_users@yahoogroups.com, "fraighttrain30"

> > bryan.wilburn@> wrote:

> > >

> > > Thanks for the input and info. It appears the Gemini is a bit more

> > > on the more intelligent side and is a tad more flexible. With the

> > > problems that could entail.

> > >

> > > But I must admit when the CGE I borrowed flipped mid guide, I

utter a

> > > few rude words.

> > >

> > > I'm also vey happy with my GM-8 & DSC. I can get the target well

> > > within the FOV on a 40mm eye piece everytime.

> > >

> > > Bryan

> > > Denver

> > >

> > > --- In Losmandy_users@yahoogroups.com, Mike Dodd mike@> wrote:

> > > >

> > > > fraighttrain30 wrote:

> > > > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> > > flip

> > > > > when the target crosses the Meridian?

> > > >

> > > > If you request a GOTO to a target on the other side of the

> > > meridian, the

> > > > mount will do a flip to reach that target. However, it will not

> > > flip

> > > > while TRACKING. It will track up to the safety limit, and stop.

> > > >

> > > > Mike

> > > > -----

> > > >

> > > > Mike Dodd

> > > > Montpelier, VA USA

> > > > astronomy.mdodd.com

> > > >

> > >

> >

>



----------------------------

#37811 Jun 5, 2008

The Ovision DEC spacer fits between the DEC Body and the top of the RA shaft plate. No need to even take the RA shaft out to add the spacer.





----- Original Message ----

From: gnowellsct tim71pos@...>

To: Losmandy_users@yahoogroups.com

Sent: Thursday, June 5, 2008 12:32:03 PM

Subject: [Losmandy_users] Re: Gemini and Meridian flip?





I think the CGE was designed to flip at meridian as a matter of

choice. The Paramount ME also flips at meridian. I used to think it

got you exactly back to where you where before the flip but I think I

heard someone say that the flip even on a Paramount, is not more

accurate than about twenty arc minutes.



Ovision in France in addition to making the worm upgrade also makes a

thick metal ring that pushes the entire dec axis out further and thus

modifies the G11 to allow 180 degree tracking from one part of the

horizon to the other. I'm not sure how that works with one's RA shaft

and all of that, seesm to me you'd need a longer RA shaft, but the

modification is available.



regards

Greg N



--- In Losmandy_users@ yahoogroups. com, "fraighttrain30"

bryan.wilburn@ ...> wrote: >

> Thanks for the input and info. It appears the Gemini is a bit more

> on the more intelligent side and is a tad more flexible. With the

> problems that could entail.

>

> But I must admit when the CGE I borrowed flipped mid guide, I utter a

> few rude words.

>

> I'm also vey happy with my GM-8 & DSC. I can get the target well

> within the FOV on a 40mm eye piece everytime.

>

> Bryan

> Denver

>

> --- In Losmandy_users@ yahoogroups. com, Mike Dodd mike@> wrote:

> >

> > fraighttrain30 wrote:

> > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> flip

> > > when the target crosses the Meridian?

> >

> > If you request a GOTO to a target on the other side of the

> meridian, the

> > mount will do a flip to reach that target. However, it will not

> flip

> > while TRACKING. It will track up to the safety limit, and stop.

> >

> > Mike

> > -----

> >

> > Mike Dodd

> > Montpelier, VA USA

> > astronomy. mdodd.com

> >

>







[Non-text portions of this message have been removed]







----------------------------

#37814 Jun 5, 2008

Hi Jay,

Yes you do because there is an extra bearing to install.

Cheers

Jon

----- Original Message -----

From: "Jay Critchfield" js3mc@...>

To: Losmandy_users@yahoogroups.com>

Sent: Thursday, June 05, 2008 8:43 PM

Subject: Re: [Losmandy_users] Re: Gemini and Meridian flip?





The Ovision DEC spacer fits between the DEC Body and the top of the RA shaft

plate. No need to even take the RA shaft out to add the spacer.





----- Original Message ----

From: gnowellsct tim71pos@...>

To: Losmandy_users@yahoogroups.com

Sent: Thursday, June 5, 2008 12:32:03 PM

Subject: [Losmandy_users] Re: Gemini and Meridian flip?





I think the CGE was designed to flip at meridian as a matter of

choice. The Paramount ME also flips at meridian. I used to think it

got you exactly back to where you where before the flip but I think I

heard someone say that the flip even on a Paramount, is not more

accurate than about twenty arc minutes.



Ovision in France in addition to making the worm upgrade also makes a

thick metal ring that pushes the entire dec axis out further and thus

modifies the G11 to allow 180 degree tracking from one part of the

horizon to the other. I'm not sure how that works with one's RA shaft

and all of that, seesm to me you'd need a longer RA shaft, but the

modification is available.



regards

Greg N



--- In Losmandy_users@ yahoogroups. com, "fraighttrain30"

bryan.wilburn@ ...> wrote:

>

> Thanks for the input and info. It appears the Gemini is a bit more

> on the more intelligent side and is a tad more flexible. With the

> problems that could entail.

>

> But I must admit when the CGE I borrowed flipped mid guide, I utter a

> few rude words.

>

> I'm also vey happy with my GM-8 & DSC. I can get the target well

> within the FOV on a 40mm eye piece everytime.

>

> Bryan

> Denver

>

> --- In Losmandy_users@ yahoogroups. com, Mike Dodd mike@> wrote:

> >

> > fraighttrain30 wrote:

> > > Does a Gemini equipped GM-11 or GM-8 do an uncommanded meridian

> flip

> > > when the target crosses the Meridian?

> >

> > If you request a GOTO to a target on the other side of the

> meridian, the

> > mount will do a flip to reach that target. However, it will not

> flip

> > while TRACKING. It will track up to the safety limit, and stop.

> >

> > Mike

> > -----

> >

> > Mike Dodd

> > Montpelier, VA USA

> > astronomy. mdodd.com

> >

>







[Non-text portions of this message have been removed]





---------------



Yahoo! Groups Links



----------------------------

#41443 Jan 31, 2009

I am using a GM8/Gemini, with GCC. Occasionally I try to do a meridian

flip when an object is near the meridian. I don't think the mount has

ever flipped (might have once, can't say for certain). Is there some

very narrow window in which the mount accepts the command, and if so,

what is it? Or, might something not be working?

Thanks,

Bob Hertel



----------------------------

#41464 Feb 1 12:22 PM

--- In Losmandy_users@yahoogroups.com, "rjhertel2001"

robert.hertel@...> wrote: >

> I am using a GM8/Gemini, with GCC. Occasionally I try to do a meridian

> flip when an object is near the meridian. I don't think the mount has

> ever flipped (might have once, can't say for certain). Is there some

> very narrow window in which the mount accepts the command, and if so,

> what is it? Or, might something not be working?

> Thanks,

> Bob Hertel

>





Sounds like you haven't set the eastern and western limits in the

Gemini. Have you ever heard the warning beeps from the controller

when you are within 10 arc-minutes of a limit? If you have set your

limits and slew toward a limit and then hear the beeps, you will then

have the Meridian Flip choice available to you from the Menu button.



Keith



----------------------------

#47671 Dec 22, 2010

I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.



The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.



Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:



Point to Aldebaran. Center star in CCD and Sync.



After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.



After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.



When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.



For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.







----------------------------

#47672 Dec 22, 2010

Are you using the PinPoint LE that comes with Maxim? PinPoint full addition seems to be able to handle this well.



But, The best thing you could do is to make sure the Polar Alignment is very accurate, this will help with the Meridian Flip and accuracy issues.

Blueman

--- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@...> wrote:

>

> I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

>

> The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

>

> Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

>

> Point to Aldebaran. Center star in CCD and Sync.

>

> After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

>

> After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

>

> When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

>

> For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

>



----------------------------

#47674 Dec 22, 2010

Hi Blueman,



Yes, I'm using PinPoint LE. Is the full addition more robust? I've found that if the telescope's coordinates are not fairly accurate, PinPoint LE usually fails. Is the full addition a lot better at this?



-Saad

--- In Losmandy_users@yahoogroups.com, "bakersfieldbiker" fblue@...> wrote:

>

> Are you using the PinPoint LE that comes with Maxim? PinPoint full addition seems to be able to handle this well.

>

> But, The best thing you could do is to make sure the Polar Alignment is very accurate, this will help with the Meridian Flip and accuracy issues.

> Blueman

>

> --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

> >

> > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> >

> > The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> >

> > Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

> >

> > Point to Aldebaran. Center star in CCD and Sync.

> >

> > After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

> >

> > After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

> >

> > When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

> >

> > For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

> >

>



----------------------------

#47675 Dec 22, 2010

Hi Saad,

Yes, the full version is much better and should be able to Plate Solve with a bit of error in the flip.

Floyd

--- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@...> wrote:

>

> Hi Blueman,

>

> Yes, I'm using PinPoint LE. Is the full addition more robust? I've found that if the telescope's coordinates are not fairly accurate, PinPoint LE usually fails. Is the full addition a lot better at this?

>

> -Saad

>

> --- In Losmandy_users@yahoogroups.com, "bakersfieldbiker" fblue@> wrote:

> >

> > Are you using the PinPoint LE that comes with Maxim? PinPoint full addition seems to be able to handle this well.

> >

> > But, The best thing you could do is to make sure the Polar Alignment is very accurate, this will help with the Meridian Flip and accuracy issues.

> > Blueman

> >

> > --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

> > >

> > > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> > >

> > > The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> > >

> > > Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

> > >

> > > Point to Aldebaran. Center star in CCD and Sync.

> > >

> > > After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

> > >

> > > After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

> > >

> > > When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

> > >

> > > For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

> > >

> >

>







----------------------------

#47676 Dec 22, 2010

If you are using an SCT, you are probably seeing the effects of mirror

flop. Your primary mirror moves as you go across the meridian. If you

aren't using an SCT, I suspect something else is moving.



PinPoint won't solve because it isn't getting the correct starting RA

and Dec from the image. If you visually align on a bright star after

the flip, that will get you close enough that PinPoint can solve an

image. Then you can solve an image, refine your alignment on the

solution and then go about your business. You shouldn't have to rebuild

the model.



If you are trying to do an unattended flip, that is a whole different

story ;>)



Jim



Saad wrote: > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

>

> The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

>

> Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

>

> Point to Aldebaran. Center star in CCD and Sync.

>

> After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

>

> After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

>

> When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

>

> For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>

>

>



----------------------------

#47677 Dec 22, 2010

Hi Jim,



When you say "visually align on a bright star", do you mean to sync on a bright star or additional align?



I'm going to guess its a sync?



Oh and I'm using a refractor.



-Saad

--- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>

> If you are using an SCT, you are probably seeing the effects of mirror

> flop. Your primary mirror moves as you go across the meridian. If you

> aren't using an SCT, I suspect something else is moving.

>

> PinPoint won't solve because it isn't getting the correct starting RA

> and Dec from the image. If you visually align on a bright star after

> the flip, that will get you close enough that PinPoint can solve an

> image. Then you can solve an image, refine your alignment on the

> solution and then go about your business. You shouldn't have to rebuild

> the model.

>

> If you are trying to do an unattended flip, that is a whole different

> story ;>)

>

> Jim

>

> Saad wrote:

> > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> >

> > The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> >

> > Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

> >

> > Point to Aldebaran. Center star in CCD and Sync.

> >

> > After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

> >

> > After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

> >

> > When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

> >

> > For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

> >

> >

> >

---------------

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

> >

>



----------------------------

#47678 Dec 23, 2010

it sounds to me like you are not building your pointing model using stars on both sides of the meridian BEFORE you start your imaging run. (please ignore if i misunderstood your process)



i had a similar problem until i created a pointing model using 3 stars on the east side of the meridian and then 2 or 3 stars on the west side. the first of the 3 stars on the east side is a sync then the other 4 (2 on east, 2 on west) are done using additional align. i don't use maxim dl but it sounds like the syncs in maxim are in fact doing "additional aligns". but from your description, it is not clear to me you have done additional aligns on both sides of the meridian. this is important for the mount to get close after a meridian flip. btw, i do this using the gemini hand controller and the ccd software.



i create the pointing model after polar alignment and objects on boths sides of the meridian will land within 3-5 arcminutes.



i recently started using ccdautopilot and WOW! what a change it has made to my life (no longer stay up all night to babysit meridian flips and everything else that is going on).



i still do the setup/alignment i described first (i don't have a permanent setup) but then i turn it all over to ccdautopilot. it controls slew to the object, does a plate solve (i bought the full version of pinpoint), controls all aspects of the image capture via ccdsoft, then handles the meridian flip and plate solves again. until i started creating a proper pointing model on both sides of the meridian, the plate solve following the flip was too far off to allow successful completion. ccdautopilot also takes care of finding a guide star before and after meridian flip.



hope that helps



Lee



--- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@...> wrote:

>

> I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

>

> The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

>







----------------------------

#47679 Dec 23, 2010

Hey Lee,

Amen to the CCDAutoPilot comment! It made my life sooo much easier.



I would also agree that the pointing model could effect this, as well as Polar Alignment and flexure type issues. Hard to be sure without more information on the system.

My MI-250 does not go much past Meridian, so I do not need to do a model on both sides, I just do a 3 star on the East, the do a Polar Alignment Correction routine with the Gemini, and I am ready to go.



Floyd

--- In Losmandy_users@yahoogroups.com, "lmbuck2000" lmbuck2000@...> wrote:

>

>

>

> it sounds to me like you are not building your pointing model using stars on both sides of the meridian BEFORE you start your imaging run. (please ignore if i misunderstood your process)

>

> i had a similar problem until i created a pointing model using 3 stars on the east side of the meridian and then 2 or 3 stars on the west side. the first of the 3 stars on the east side is a sync then the other 4 (2 on east, 2 on west) are done using additional align. i don't use maxim dl but it sounds like the syncs in maxim are in fact doing "additional aligns". but from your description, it is not clear to me you have done additional aligns on both sides of the meridian. this is important for the mount to get close after a meridian flip. btw, i do this using the gemini hand controller and the ccd software.

>

> i create the pointing model after polar alignment and objects on boths sides of the meridian will land within 3-5 arcminutes.

>

> i recently started using ccdautopilot and WOW! what a change it has made to my life (no longer stay up all night to babysit meridian flips and everything else that is going on).

>

> i still do the setup/alignment i described first (i don't have a permanent setup) but then i turn it all over to ccdautopilot. it controls slew to the object, does a plate solve (i bought the full version of pinpoint), controls all aspects of the image capture via ccdsoft, then handles the meridian flip and plate solves again. until i started creating a proper pointing model on both sides of the meridian, the plate solve following the flip was too far off to allow successful completion. ccdautopilot also takes care of finding a guide star before and after meridian flip.

>

> hope that helps

>

> Lee

>

>

> --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

> >

> > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> >

> > The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> >

>



----------------------------

#47680 Dec 23, 2010

Hi Saad



Yes, I mean a sync from MaxIm without additional align.



Since you aren't using an SCT, I would take a close look at flexure. Is

your camera to telescope connection secure? Are you using tube rings or

is the OTA solidly mounted to the mount and so forth. I'm no expert on

flexure since my cross to bear is mirror flop.



As someone else mentioned you need to be using stars on both sides of

the meridian to build your model. That by itself may clear up your problem.



Just how big is your FOV? After you make your meridian flip, is the

target still located anywhere in the FOV?



Finally, as a last resort, John Winfield has a utility called SkySolve

that can solve an image without any prior knowledge of where in the sky

it was taken. You can find out more about it at

winfij.homeip.net/development/SkySolve/index.html



It requires a full license for PinPoint and a minimum FOV of at least 18

min. At 18 min, it takes 4 days of computation (you only do this step

once) to build the data base. But, I'm told it does work. You can find

a support forum for SkySolve at forums.dc3.com/forumdisplay.php?f=60



Jim



Saad wrote: > Hi Jim,

>

> When you say "visually align on a bright star", do you mean to sync on a bright star or additional align?

>

> I'm going to guess its a sync?

>

> Oh and I'm using a refractor.

>

> -Saad

>

> --- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>

>> If you are using an SCT, you are probably seeing the effects of mirror

>> flop. Your primary mirror moves as you go across the meridian. If you

>> aren't using an SCT, I suspect something else is moving.

>>

>> PinPoint won't solve because it isn't getting the correct starting RA

>> and Dec from the image. If you visually align on a bright star after

>> the flip, that will get you close enough that PinPoint can solve an

>> image. Then you can solve an image, refine your alignment on the

>> solution and then go about your business. You shouldn't have to rebuild

>> the model.

>>

>> If you are trying to do an unattended flip, that is a whole different

>> story ;>)

>>

>> Jim

>>

>> Saad wrote:

>>

>>> I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

>>>

>>> The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

>>>

>>> Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

>>>

>>> Point to Aldebaran. Center star in CCD and Sync.

>>>

>>> After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

>>>

>>> After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

>>>

>>> When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

>>>

>>> For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

>>>

>>>

>>>

---------------

>>>

>>> Yahoo! Groups Links

>>>

>>>

>>>

>>>

>>>

>>>

>

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>

>

>







----------------------------

#47681 Dec 23, 2010

You might have hit the nail on the head!



I did not create a pointing model on the west side of the meridian and only did it on the east. To clarify, here is what I SHOULD be doing:



1. Sync on a bright known star towards the east.

2. Additional align on two more stars (in my case, just slew the telescope a bit and plate solve. Then perform an additional align with Maxim DL.)



3. Do a meridian flip.



4. Additional align on two or three more coordinates.



CCDAutopilot does sound quite amazing! I wasn't aware that it was helpful for field setups as well. I will take a closer look into it.



I am not 100% sure that Maxim DL performs an Additional Align. However, here is what I usually do these days. I sync on Aldebaran using the hand controller. Once this is done, I connect Maxim DL to my mount and make sure "Sync Performs Additional Align" checkbox is checked in the Gemini Driver settings. I then slew the telescope to a random spot (at the same side of the meridian) and do a plate solve. Once the plate solve is done, I click "sync" in the maxim telescope tab. Then, I hope, performs an additional align instead of a Sync.



Anybody with some experience regarding this? Is there anyway I can check using the hand controller weather an additional align was performed?

--- In Losmandy_users@yahoogroups.com, "lmbuck2000" lmbuck2000@...> wrote:

>

>

>

> it sounds to me like you are not building your pointing model using stars on both sides of the meridian BEFORE you start your imaging run. (please ignore if i misunderstood your process)

>

> i had a similar problem until i created a pointing model using 3 stars on the east side of the meridian and then 2 or 3 stars on the west side. the first of the 3 stars on the east side is a sync then the other 4 (2 on east, 2 on west) are done using additional align. i don't use maxim dl but it sounds like the syncs in maxim are in fact doing "additional aligns". but from your description, it is not clear to me you have done additional aligns on both sides of the meridian. this is important for the mount to get close after a meridian flip. btw, i do this using the gemini hand controller and the ccd software.

>

> i create the pointing model after polar alignment and objects on boths sides of the meridian will land within 3-5 arcminutes.

>

> i recently started using ccdautopilot and WOW! what a change it has made to my life (no longer stay up all night to babysit meridian flips and everything else that is going on).

>

> i still do the setup/alignment i described first (i don't have a permanent setup) but then i turn it all over to ccdautopilot. it controls slew to the object, does a plate solve (i bought the full version of pinpoint), controls all aspects of the image capture via ccdsoft, then handles the meridian flip and plate solves again. until i started creating a proper pointing model on both sides of the meridian, the plate solve following the flip was too far off to allow successful completion. ccdautopilot also takes care of finding a guide star before and after meridian flip.

>

> hope that helps

>

> Lee

>

>

> --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

> >

> > I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> >

> > The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> >

>



----------------------------

#47682 Dec 23, 2010

Thanks for the clarification. Now that I've understood that I also need to have done additional aligns on the west side of the meridian it makes more sense.



One thing though, once I've created a pointing model, with coordinates/stars on both sides of the meridian, and I have to do a flip will I still need to perform a sync afterwards?



For some reason, I was under the impression that doing a Sync will remove the previous pointing model. I am assuming this is incorrect and performing a Sync will merely make the mount realize that it was slightly off but the pointing model is still correct and to keep on applying it.



Regarding flexure, I am using hinged rings not the 3-point ones. The telescope is quite solidly mounted, as far as I can tell.



My field of view is approximately 134.9' x 101.5'. The target does not land inside the FOV, but its relatively close. I'm hoping that having done aligns on both sides of the meridian will help with this matter.

--- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>

> Hi Saad

>

> Yes, I mean a sync from MaxIm without additional align.

>

> Since you aren't using an SCT, I would take a close look at flexure. Is

> your camera to telescope connection secure? Are you using tube rings or

> is the OTA solidly mounted to the mount and so forth. I'm no expert on

> flexure since my cross to bear is mirror flop.

>

> As someone else mentioned you need to be using stars on both sides of

> the meridian to build your model. That by itself may clear up your problem.

>

> Just how big is your FOV? After you make your meridian flip, is the

> target still located anywhere in the FOV?

>

> Finally, as a last resort, John Winfield has a utility called SkySolve

> that can solve an image without any prior knowledge of where in the sky

> it was taken. You can find out more about it at

> winfij.homeip.net/development/SkySolve/index.html

>

> It requires a full license for PinPoint and a minimum FOV of at least 18

> min. At 18 min, it takes 4 days of computation (you only do this step

> once) to build the data base. But, I'm told it does work. You can find

> a support forum for SkySolve at forums.dc3.com/forumdisplay.php?f=60

>

> Jim

>

> Saad wrote:

> > Hi Jim,

> >

> > When you say "visually align on a bright star", do you mean to sync on a bright star or additional align?

> >

> > I'm going to guess its a sync?

> >

> > Oh and I'm using a refractor.

> >

> > -Saad

> >

> > --- In Losmandy_users@yahoogroups.com, Jim Jones albiero@> wrote:

> >

> >> If you are using an SCT, you are probably seeing the effects of mirror

> >> flop. Your primary mirror moves as you go across the meridian. If you

> >> aren't using an SCT, I suspect something else is moving.

> >>

> >> PinPoint won't solve because it isn't getting the correct starting RA

> >> and Dec from the image. If you visually align on a bright star after

> >> the flip, that will get you close enough that PinPoint can solve an

> >> image. Then you can solve an image, refine your alignment on the

> >> solution and then go about your business. You shouldn't have to rebuild

> >> the model.

> >>

> >> If you are trying to do an unattended flip, that is a whole different

> >> story ;>)

> >>

> >> Jim

> >>

> >> Saad wrote:

> >>

> >>> I try to avoid meridian flips as much as possible, but considering the long time it takes to make a decent narrowband image a meridian flip becomes pretty necessary when the target crosses the meridian.

> >>>

> >>> The problem is, whenever I do a meridian flip I land somewhat near the target but not near enough as I'd like. Furthermore, its hard to find where I'm precisely pointing as plate solves in MaximDL fail. My field of view is relatively big and if the flip landed my target somewhere in the FOV, it'd make life much easier.

> >>>

> >>> Has anyone else dealt with this here? If so, how did you overcome it? Here is how I build my pointing model these days:

> >>>

> >>> Point to Aldebaran. Center star in CCD and Sync.

> >>>

> >>> After this, I move the telescope in RA+ and shoot a 15s exposure. I plate solve the image and find the true center and do a sync in Maxim DL (I have "Sync Performs Additional Align" in the Gemini Driver checked, so I assume this essentially performs an Additional Align on Gemini). I repeat this a few times, performing a sync in MaximDL.

> >>>

> >>> After this, I slew to my target, perform one last 'sync' in MaximDL and start exposing.

> >>>

> >>> When I do a meridian flip, the target does not land in FOV. All the plate solves fail and I'm essentially blind. I usually have to build my pointing model from scratch.

> >>>

> >>> For what its worth, I have "Gemini expects J2000 coordinates" checked in the Gemini Driver and I always send J2000 Solved coordinates to Gemini from MaximDL.

> >>>

> >>>

> >>>

---------------

> >>>

> >>> Yahoo! Groups Links

> >>>

> >>>

> >>>

> >>>

> >>>

> >>>

> >

> >

> >

> >

---------------

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

> >

>







----------------------------

#47683 Dec 23, 2010

i don't know what maxim knows about your mount and how the pointing model is created, but i was always under the impression that to build a proper pointing model with the gemini you need to additional align on 3 or more stars each separated by at least one hour in RA. you say >> I then slew the telescope to a random spot <. do you have the recommended RA separation to build an accurate model.



i guess with the maxim/plate solve approach you are doing an "additional align" on some general RA/DEC coordinates rather than some specific star -- which should be fine as long as maxim truly is doing an additional align (and not really doing a sync) and the RA of each object is separated by 1hr or more.



one way to check if an additional align has been done by maxim is by using the hand controller there will be a menu choice to "reset alignment" under align telescope if the last 'sync' from maxim truly was an additional align command.





lee



--- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@...> wrote:

>

> You might have hit the nail on the head!

>

> I did not create a pointing model on the west side of the meridian and only did it on the east. To clarify, here is what I SHOULD be doing:

>

> 1. Sync on a bright known star towards the east.

> 2. Additional align on two more stars (in my case, just slew the telescope a bit and plate solve. Then perform an additional align with Maxim DL.)

>

> 3. Do a meridian flip.

>

> 4. Additional align on two or three more coordinates.

>

> CCDAutopilot does sound quite amazing! I wasn't aware that it was helpful for field setups as well. I will take a closer look into it.

>

> I am not 100% sure that Maxim DL performs an Additional Align. However, here is what I usually do these days. I sync on Aldebaran using the hand controller. Once this is done, I connect Maxim DL to my mount and make sure "Sync Performs Additional Align" checkbox is checked in the Gemini Driver settings. I then slew the telescope to a random spot (at the same side of the meridian) and do a plate solve. Once the plate solve is done, I click "sync" in the maxim telescope tab. Then, I hope, performs an additional align instead of a Sync.

>

> Anybody with some experience regarding this? Is there anyway I can check using the hand controller weather an additional align was performed?

>



----------------------------

#47684 Dec 23, 2010

I went to find the documentation of the Gemini ASCOM driver and here's what it says about the additional align checkbox:



Synch Performs Additional Align . Controls the effect of a synchronize command received from a client program. ASCOM only implements a single synchronize command, it has no concept of synchronizing to add to a model, setting this parameter allows you to build a Gemini pointing model by using a `Goto', `center' (in eyepiece or camera), and `synchronize' sequence in your favorite planetarium program.



So, since I check this I believe I'm pretty set. This just allows me to build a pointing model MUCH quicker than centering bright stars as I can slew to any area of the sky given that it is in the same part of the meridian and the separation is greater than 1 hour angle.



To reiterate, here is what I should do tonight to build my pointing model:



a) Do a cold start to erase everything and start fresh.



b) Sync on a bright star - Cappella or Aldebaran these days.



c) Additional align on two further coordinates separated by more than 1 hour angle and on the same side of the meridian.



-- here is where I'm slightly confused:



d) Slew to the western part of the sky and do an additional align on two more stars



OR



d) Do a meridian flip and THEN additional align on two more stars



--Do I need to do a SYNC again when the mount performs a meridian flip?



-Saad

--- In Losmandy_users@yahoogroups.com, "lmbuck2000" lmbuck2000@...> wrote:

>

> i don't know what maxim knows about your mount and how the pointing model is created, but i was always under the impression that to build a proper pointing model with the gemini you need to additional align on 3 or more stars each separated by at least one hour in RA. you say >> I then slew the telescope to a random spot <. do you have the recommended RA separation to build an accurate model.

>

> i guess with the maxim/plate solve approach you are doing an "additional align" on some general RA/DEC coordinates rather than some specific star -- which should be fine as long as maxim truly is doing an additional align (and not really doing a sync) and the RA of each object is separated by 1hr or more.

>

> one way to check if an additional align has been done by maxim is by using the hand controller there will be a menu choice to "reset alignment" under align telescope if the last 'sync' from maxim truly was an additional align command.

>

>

> lee

>

>

> --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

> >

> > You might have hit the nail on the head!

> >

> > I did not create a pointing model on the west side of the meridian and only did it on the east. To clarify, here is what I SHOULD be doing:

> >

> > 1. Sync on a bright known star towards the east.

> > 2. Additional align on two more stars (in my case, just slew the telescope a bit and plate solve. Then perform an additional align with Maxim DL.)

> >

> > 3. Do a meridian flip.

> >

> > 4. Additional align on two or three more coordinates.

> >

> > CCDAutopilot does sound quite amazing! I wasn't aware that it was helpful for field setups as well. I will take a closer look into it.

> >

> > I am not 100% sure that Maxim DL performs an Additional Align. However, here is what I usually do these days. I sync on Aldebaran using the hand controller. Once this is done, I connect Maxim DL to my mount and make sure "Sync Performs Additional Align" checkbox is checked in the Gemini Driver settings. I then slew the telescope to a random spot (at the same side of the meridian) and do a plate solve. Once the plate solve is done, I click "sync" in the maxim telescope tab. Then, I hope, performs an additional align instead of a Sync.

> >

> > Anybody with some experience regarding this? Is there anyway I can check using the hand controller weather an additional align was performed?

> >

>







----------------------------

#47685 Dec 23, 2010

Saad



Sounds like you are getting there. You want to do a meridian flip to the

western part of the sky. At that point, pinpoint probably won't be able

to solve an image because it won't know where it's at. So I always slew

to a bright star and center it in the image and I do an sync. Now

pinpoint knows where it's at and you can finish building the model on

the western part of the sky.



I would probably add a couple more stars on each side of the sky.



This may not solve your problem with the meridian flip. But you have to

get a good model built before you can do anything else. And maybe, just

maybe this will take care of the problem.



One last thought 134.9' x 101.5' is a huge FOV. You may be a prime

candidate for SkySolve.



Jim



Saad wrote: > I went to find the documentation of the Gemini ASCOM driver and here's what it says about the additional align checkbox:

>

> Synch Performs Additional Align . Controls the effect of a synchronize command received from a client program. ASCOM only implements a single synchronize command, it has no concept of synchronizing to add to a model, setting this parameter allows you to build a Gemini pointing model by using a `Goto', `center' (in eyepiece or camera), and `synchronize' sequence in your favorite planetarium program.

>

> So, since I check this I believe I'm pretty set. This just allows me to build a pointing model MUCH quicker than centering bright stars as I can slew to any area of the sky given that it is in the same part of the meridian and the separation is greater than 1 hour angle.

>

> To reiterate, here is what I should do tonight to build my pointing model:

>

> a) Do a cold start to erase everything and start fresh.

>

> b) Sync on a bright star - Cappella or Aldebaran these days.

>

> c) Additional align on two further coordinates separated by more than 1 hour angle and on the same side of the meridian.

>

> -- here is where I'm slightly confused:

>

> d) Slew to the western part of the sky and do an additional align on two more stars

>

> OR

>

> d) Do a meridian flip and THEN additional align on two more stars

>

> --Do I need to do a SYNC again when the mount performs a meridian flip?

>

> -Saad

>

> --- In Losmandy_users@yahoogroups.com, "lmbuck2000" lmbuck2000@...> wrote:

>

>> i don't know what maxim knows about your mount and how the pointing model is created, but i was always under the impression that to build a proper pointing model with the gemini you need to additional align on 3 or more stars each separated by at least one hour in RA. you say >> I then slew the telescope to a random spot <. do you have the recommended RA separation to build an accurate model.

>>

>> i guess with the maxim/plate solve approach you are doing an "additional align" on some general RA/DEC coordinates rather than some specific star -- which should be fine as long as maxim truly is doing an additional align (and not really doing a sync) and the RA of each object is separated by 1hr or more.

>>

>> one way to check if an additional align has been done by maxim is by using the hand controller there will be a menu choice to "reset alignment" under align telescope if the last 'sync' from maxim truly was an additional align command.

>>

>>

>> lee

>>

>>

>> --- In Losmandy_users@yahoogroups.com, "Saad" saad_abbasi@> wrote:

>>

>>> You might have hit the nail on the head!

>>>

>>> I did not create a pointing model on the west side of the meridian and only did it on the east. To clarify, here is what I SHOULD be doing:

>>>

>>> 1. Sync on a bright known star towards the east.

>>> 2. Additional align on two more stars (in my case, just slew the telescope a bit and plate solve. Then perform an additional align with Maxim DL.)

>>>

>>> 3. Do a meridian flip.

>>>

>>> 4. Additional align on two or three more coordinates.

>>>

>>> CCDAutopilot does sound quite amazing! I wasn't aware that it was helpful for field setups as well. I will take a closer look into it.

>>>

>>> I am not 100% sure that Maxim DL performs an Additional Align. However, here is what I usually do these days. I sync on Aldebaran using the hand controller. Once this is done, I connect Maxim DL to my mount and make sure "Sync Performs Additional Align" checkbox is checked in the Gemini Driver settings. I then slew the telescope to a random spot (at the same side of the meridian) and do a plate solve. Once the plate solve is done, I click "sync" in the maxim telescope tab. Then, I hope, performs an additional align instead of a Sync.

>>>

>>> Anybody with some experience regarding this? Is there anyway I can check using the hand controller weather an additional align was performed?

>>>

>>>

>

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>

>

>

>



----------------------------

#47686 Dec 23, 2010

-- here is where I'm slightly confused:

>

> d) Slew to the western part of the sky and do an additional align on two more stars



LB> YES

>

> OR

>

> d) Do a meridian flip and THEN additional align on two more stars



LB> your mount will require a meridian flip to point to a star in the western sky -- it will do it automatically with the goto (unless you have some very odd settings elsewhere but i wont go into that).



you do not have to explicitly tell it to do a meridian flip when a goto requires it - it just happens. (when you are pointing to a star in the eastern sky, the telescope is on the west side of the mount. to point to a star in the west, it will flip to the east side of the mount).

>

> --Do I need to do a SYNC again when the mount performs a meridian flip?

>



LB> NO, don't sync. you may need to use the hand control to position the goto star in the center of the field (may need to use a guide scope). but for the subsequent align it should be pretty good. this is exactly the problem you are trying to correct for before you start the imaging run. let the mount know how far off it is when the system weight shifts from west to east (or vice versa)



Lee







----------------------------

#47687 Dec 23, 2010

The folks that write Maxim answered a question on the Maxim list about how

to sync between two observation sessions. I have been using this technique

and it works perfectly. I have used it on my own meridian flips.





1. Point roughly at the target, PinPoint solve and sync. You now have a

highly accurate position for the telescope.



2. Load up a previous image that you want to align with. PinPoint solve

it.



3. Right click on the old image and select Slew to PinPoint Center.







Rob Hawley



----------------------------

#47688 Dec 23, 2010

Lee



When he is building the model, on the first star on the west side he is

going to have to center the star in the center of the image and do a

sync on it. Otherwise he can build his model.



Jim





lmbuck2000 wrote: >> -- here is where I'm slightly confused:

>>

>> d) Slew to the western part of the sky and do an additional align on two more stars

>>

>

> LB> YES

>

>

>> OR

>>

>> d) Do a meridian flip and THEN additional align on two more stars

>>

>

> LB> your mount will require a meridian flip to point to a star in the western sky -- it will do it automatically with the goto (unless you have some very odd settings elsewhere but i wont go into that).

>

> you do not have to explicitly tell it to do a meridian flip when a goto requires it - it just happens. (when you are pointing to a star in the eastern sky, the telescope is on the west side of the mount. to point to a star in the west, it will flip to the east side of the mount).

>

>

>> --Do I need to do a SYNC again when the mount performs a meridian flip?

>>

>>

>

> LB> NO, don't sync. you may need to use the hand control to position the goto star in the center of the field (may need to use a guide scope). but for the subsequent align it should be pretty good. this is exactly the problem you are trying to correct for before you start the imaging run. let the mount know how far off it is when the system weight shifts from west to east (or vice versa)

>

> Lee

>

>

>

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>

>

>



----------------------------

#47689 Dec 24, 2010

Incidentally with Argo Navis I get all-sky pointing accuracy of 3-5 arc minutes. My hunch is that the meridian flip + backlash are the main reasons why the pointing accuracy of even the best go-to systems is around the same as Argo Navis with its measly 10k tics encoder resolution.



regards

Greg N



--- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>

> Lee

>

> When he is building the model, on the first star on the west side he is

> going to have to center the star in the center of the image and do a

> sync on it. Otherwise he can build his model.

>

> Jim

>

>

> lmbuck2000 wrote:

> >> -- here is where I'm slightly confused:

> >>

> >> d) Slew to the western part of the sky and do an additional align on two more stars

> >>

> >

> > LB> YES

> >

> >

> >> OR

> >>

> >> d) Do a meridian flip and THEN additional align on two more stars

> >>

> >

> > LB> your mount will require a meridian flip to point to a star in the western sky -- it will do it automatically with the goto (unless you have some very odd settings elsewhere but i wont go into that).

> >

> > you do not have to explicitly tell it to do a meridian flip when a goto requires it - it just happens. (when you are pointing to a star in the eastern sky, the telescope is on the west side of the mount. to point to a star in the west, it will flip to the east side of the mount).

> >

> >

> >> --Do I need to do a SYNC again when the mount performs a meridian flip?

> >>

> >>

> >

> > LB> NO, don't sync. you may need to use the hand control to position the goto star in the center of the field (may need to use a guide scope). but for the subsequent align it should be pretty good. this is exactly the problem you are trying to correct for before you start the imaging run. let the mount know how far off it is when the system weight shifts from west to east (or vice versa)

> >

> > Lee

> >

> >

> >

> >

> >

> >

---------------

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

> >

>



----------------------------

#47690 Dec 24, 2010

if he has already synced on a star on the east side (which he says he did), you do not need to sync on a star again on the west. this being 'sync' in gemini terms, not maxim terms which seems to optionally be an 'additional align' instead of a sync. syncing (gemini term) does not add/build to the pointing model, it only resets where the scope thinks it is. it is important to actually build the pointing model with stars from both sides using additional aligns.



Lee

--- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>

> Lee

>

> When he is building the model, on the first star on the west side he is

> going to have to center the star in the center of the image and do a

> sync on it. Otherwise he can build his model.

>

> Jim

>

>

> lmbuck2000 wrote:

> >> -- here is where I'm slightly confused:

> >>

> >> d) Slew to the western part of the sky and do an additional align on two more stars

> >>

> >

> > LB> YES

> >

> >

> >> OR

> >>

> >> d) Do a meridian flip and THEN additional align on two more stars

> >>

> >

> > LB> your mount will require a meridian flip to point to a star in the western sky -- it will do it automatically with the goto (unless you have some very odd settings elsewhere but i wont go into that).

> >

> > you do not have to explicitly tell it to do a meridian flip when a goto requires it - it just happens. (when you are pointing to a star in the eastern sky, the telescope is on the west side of the mount. to point to a star in the west, it will flip to the east side of the mount).

> >

> >

> >> --Do I need to do a SYNC again when the mount performs a meridian flip?

> >>

> >>

> >

> > LB> NO, don't sync. you may need to use the hand control to position the goto star in the center of the field (may need to use a guide scope). but for the subsequent align it should be pretty good. this is exactly the problem you are trying to correct for before you start the imaging run. let the mount know how far off it is when the system weight shifts from west to east (or vice versa)

> >

> > Lee

> >

> >

> >

> >

> >

> >

---------------

> >

> > Yahoo! Groups Links

> >

> >

> >

> >

> >

>







----------------------------

#47691 Dec 24, 2010

I have a simple way of doing this. I am usually imaging an object that is

well toward the east so I can do a longer run. I pick about six alignment

stars spread out from east to west. I try to avoid stars that are directly

overhead so I don't have to get down on my knees so much. I do a simple

polar alignment using the polar scope. I have the mount goto the western

most alignment star and start there doing additional alignments as I work

back to the east. At some point the mount will flip itself. I continue

east until I am on the alignment star closest to my target. I sinc on that

star and then goto the target. Usually between midnight and 1 a.m. I

initiate an meridian flip. Since I added the OPWB to the GM-8 the flip has

put the target in the FOV every time. The FOV is a little over one degree so

the mount is flipping to within about 45 arcminutes of the target, and

frequently even better. This is good enough for my purposes.

Steve ----- Original Message -----

From: "lmbuck2000" lmbuck2000@...>

To: Losmandy_users@yahoogroups.com>

Sent: Friday, December 24, 2010 9:25 AM

Subject: [Losmandy_users] Re: Handling a Meridian Flip





> if he has already synced on a star on the east side (which he says he

> did), you do not need to sync on a star again on the west. this being

> 'sync' in gemini terms, not maxim terms which seems to optionally be an

> 'additional align' instead of a sync. syncing (gemini term) does not

> add/build to the pointing model, it only resets where the scope thinks it

> is. it is important to actually build the pointing model with stars from

> both sides using additional aligns.

>

> Lee

>

> --- In Losmandy_users@yahoogroups.com, Jim Jones albiero@...> wrote:

>>

>> Lee

>>

>> When he is building the model, on the first star on the west side he is

>> going to have to center the star in the center of the image and do a

>> sync on it. Otherwise he can build his model.

>>

>> Jim

>>

>>

>> lmbuck2000 wrote:

>> >> -- here is where I'm slightly confused:

>> >>

>> >> d) Slew to the western part of the sky and do an additional align on

>> >> two more stars

>> >>

>> >

>> > LB> YES

>> >

>> >

>> >> OR

>> >>

>> >> d) Do a meridian flip and THEN additional align on two more stars

>> >>

>> >

>> > LB> your mount will require a meridian flip to point to a star in the

>> > western sky -- it will do it automatically with the goto (unless you

>> > have some very odd settings elsewhere but i wont go into that).

>> >

>> > you do not have to explicitly tell it to do a meridian flip when a goto

>> > requires it - it just happens. (when you are pointing to a star in the

>> > eastern sky, the telescope is on the west side of the mount. to point

>> > to a star in the west, it will flip to the east side of the mount).

>> >

>> >

>> >> --Do I need to do a SYNC again when the mount performs a meridian

>> >> flip?

>> >>

>> >>

>> >

>> > LB> NO, don't sync. you may need to use the hand control to position

>> > the goto star in the center of the field (may need to use a guide

>> > scope). but for the subsequent align it should be pretty good. this

>> > is exactly the problem you are trying to correct for before you start

>> > the imaging run. let the mount know how far off it is when the system

>> > weight shifts from west to east (or vice versa)

>> >

>> > Lee

>> >

>> >

>> >

>> >

>> >

>> >

---------------

>> >

>> > Yahoo! Groups Links

>> >

>> >

>> >

>> >

>> >

>>

>

>

>

>

---------------

>

> Yahoo! Groups Links

>

>

>



----------------------------

#47699 Dec 28, 2010

--UPDATE



I have been using a pointing model of 4 stars on the east and 3 on the west and it seems to have solved my problem! I can now do a meridian flip after imaging from the east side, plate solve, sync and be on target within a few minutes to continue my exposure!



Thank you everyone!



-Saad



----------------------------

#54572 Sep 2, 2014

Hi all,��I.m embarrassed to ask this question but can.t resolve theproblem on my own, so here goes. How does one get a GM-8 with Gemini 1.4 to doa meridian flip? When I.m imaging with the scope in the W side of the meridianI have to wait until the object is well past the meridian before I can issueanother goto command and get the scope on the E side.��I.ve read the manual a dozen times and tried various combinationsof safety limit and goto limits but I never see the .meridian flip. command inthe hand controller.�� There must be a betterway then waiting for the object of get 15+ deg past the meridian before doing another goto command.

What am I missing?��Any help would be appreciated.



----------------------------

#54574 Sep 2, 2014

Dave,

Thanks for the reply. The problem is I never see the Meridian flip command in the quick menu. Is it possible it was somehow erased?

I'll play around with the safety limits again. to determine if they are set in such a way that they are keeping the menu from appearing.







----------------------------

#54576 Sep 2, 2014

On 03/09/2014 8:10 AM, Mike Tappermitapp2@... [Losmandy_users] wrote:

.Dave,

Thanksfor the reply. The problem is I never see the Meridianflip command in the quick menu. Is it possible it wassomehow erased?



----------------------------

#54577 Sep 3, 2014

Andrew, I've tried it both with full and reduced menus..



----------------------------

#54578 Sep 3, 2014

The quick menue is accessible by holding down the menu button for a few secs, then let go once the option you want is displayed.That said, if you use a computer for imaging, you can flip the mount from the gemini.net virtual hand control.Jeremy



----------------------------

#54579 Sep 3, 2014

The meridian flipoption will only appear when the safety limits will allow it. Example say youhave your safety limits set at one hundred degrees East and a hundred degreesWest and you are at 99 decrees on the Eastside and want to do a flip. Since yourshort of the hundred degrees the flip will not be allowed and you will not getthe option and no option will appear!��Goodluck



----------------------------

#58871 Mar 7, 2017

Hi!

I'm trying to get the auto-meridian flip in Ekos/INDI to work on my G-11, and I'd need to understand a more basic question:

When the mount tracks a star, and that star crosses the meridian - what happens if I issue a GOTO to that star? (this is what Ekos does and expects a meridian flip)My G-11 does nothing. But sometimes it does a meridian flip and goes to the star from the "other" side. But I've not been able to figure out when this happens.

So: anyone knows when Gemini does a meridian flip when I issue a GOTO to the "wrong" side of the meridian, and when it just takes the shortest route? Has it anything to do with limits that I set with the HC, or what determines this?

(I am well aware that Gemini on its own does not do an auto meridian flip - I just need to know under what conditions a GOTO command will trigger a meridian flip).

Magnus



----------------------------

#58872 Mar 7, 2017

Hi Magnus,

Gemini does not flip at the meridian, it flips at the Goto limit. This is defaulted to 2.5 degrees earlier than the Western safety limit, but can be changed in settings. Obviously, the safety limit itself can also be adjusted.

For example, if your safety limit is set to 100 degrees, then the mount will flip if a Goto command will take it past the 97.5 degree mark. But, the goto target must be reachable from the other side of the mount, else Gemini will not flip. If your Eastern safety limit is set too conservatively, you may find that a number of targets will not be reachable from that side of the pier.

Regards,

�� �� -Paul



----------------------------

#58873 Mar 7, 2017

Hi!

Perfect! This was precisely the information I needed! So then I can manipulate the point of auto-meridian flip by setting my limits in a smart way. Great! Thanks!!

Magnus



----------------------------

#58874 Mar 7, 2017

Also thanks Paul... I had been wondering the same thing myself.. I'm glad Magnus raised the question!

So here is another question....

Ideally I want to have a meridian flip at some number of degrees past the meridian (say 10 degrees just as an example) if moving (slewing) either West or East. . In other words there are 2 RA positions in which the scope will flip. .

(I am not sure that Gemini is set to accomplish that.. Maybe it only will allow a single RA angle and always flip there. .Right now I use the Gemini.net applet to force a meridian flip when I want that...it does not occur automatically.)

And I want the mount to totally stop when RA reaches either 90 degrees past meridian in either East or West directions.

How should I set up the limits for this? . (Or what are the formulas to calculate limits?)

Many thanks,Michael



----------------------------

#58875 Mar 7, 2017

You're welcome.



> Ideally I want to have a meridian flip at some number of degrees past the meridian (say 10 degrees just as an example) if moving (slewing) either West or East.��

Automatic meridian flip only makes sense at the Western limit, in my opinion. Once the mount flips from West to East, it can continue tracking for many more hours. Now, if the mount was to auto-flip from East to West, there likely would be only minutes left before tracking would run into the Western safety limit. Probably not what you'd want to happen automatically, but you can always do this manually.

Regards,

�� ��-Paul



----------------------------

#58876 Mar 7, 2017

Yes.. That's correct...I usually set up my scope saddle to be over to the East, .so the scope will get the most exposure moving West without having a flip. .

Thanks again,.

Michael.



----------------------------

#59551 Jul 6, 2017

I went to bed last night expecting my photo shoot would be fine like on other nights. Everything was pointing correctly. When I woke up this morning, I found that the shoot had aborted and that my telescope was pointed exactly 180 degrees in the opposite direction. What causes these burps? I wrote and earlier post where this type of thing happens at startup, when Gemini attempts a western meridian flip with an eastern star which causes an error.

Rob



----------------------------

#59552 Jul 6, 2017

Hi Rob, 180 degrees in which direction? Where was the scope supposed to be and where was it in relation to that position? Was it RA or DEC axis that was incorrect (or both)?

What software are you using to automate the shooting?��

Regards,

�� �� ��-Paul



----------------------------

#59553 Jul 6, 2017

Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob



----------------------------

#59555 Jul 6, 2017

I.ve had something similar, but when SGP tells it to park itself. Instead of going to the home position, it slews until it hits the safety stop to the west.







When I go out to look at it, the scope is pointing about 40 degrees below horizon to the north, and the RA axis is pointing about 15 degrees below horizon to the west. Counter weights high in the east.







This has happened twice during an automation run with SGP parking it at the end of a sequence, the past couple of weeks.







Previously this worked fine.



I.m perplexed at what is going on. It.s not going to the home position, nor the cold start position, yet everything ran fine for the night, until then.



Doug







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 12:02 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.











Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob











[Non-text portions of this message have been removed]







----------------------------

#59556 Jul 6, 2017

1st step, replace the memory backup battery.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:11

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



I.ve had something similar, but when SGP tells it to park itself. Instead of going to the home position, it slews until it hits the safety stop to the west.







When I go out to look at it, the scope is pointing about 40 degrees below horizon to the north, and the RA axis is pointing about 15 degrees below horizon to the west. Counter weights high in the east.







This has happened twice during an automation run with SGP parking it at the end of a sequence, the past couple of weeks.







Previously this worked fine.



I.m perplexed at what is going on. It.s not going to the home position, nor the cold start position, yet everything ran fine for the night, until then.



Doug







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 12:02 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.











Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob











[Non-text portions of this message have been removed]







---------------

Posted by: "Doug Bock" dbock1@...>

---------------





---------------



Yahoo Groups Links



----------------------------

#59557 Jul 6, 2017

Hmm. I would think that battery would last longer than 9 months.



Doug







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 4:24 PM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.











1st step, replace the memory backup battery.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:11

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



I.ve had something similar, but when SGP tells it to park itself. Instead of going to the home position, it slews until it hits the safety stop to the west.



When I go out to look at it, the scope is pointing about 40 degrees below horizon to the north, and the RA axis is pointing about 15 degrees below horizon to the west. Counter weights high in the east.



This has happened twice during an automation run with SGP parking it at the end of a sequence, the past couple of weeks.



Previously this worked fine.



I.m perplexed at what is going on. It.s not going to the home position, nor the cold start position, yet everything ran fine for the night, until then.



Doug



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 12:02 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob



[Non-text portions of this message have been removed]



---------------

Posted by: "Doug Bock" dbock1@...>

---------------



---------------



Yahoo Groups Links











[Non-text portions of this message have been removed]



----------------------------

#59558 Jul 7, 2017

Fair point ... worth checking the voltage on it anyway.



I assume you have the battery life modification installed if yours is an early G1? www.gemini-2.com/Gemini-1%20mods.php>



The later boards have this change implemented using an SMD resistor.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:58

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



Hmm. I would think that battery would last longer than 9 months.



Doug







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 4:24 PM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.











1st step, replace the memory backup battery.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:11

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



I.ve had something similar, but when SGP tells it to park itself. Instead of going to the home position, it slews until it hits the safety stop to the west.



When I go out to look at it, the scope is pointing about 40 degrees below horizon to the north, and the RA axis is pointing about 15 degrees below horizon to the west. Counter weights high in the east.



This has happened twice during an automation run with SGP parking it at the end of a sequence, the past couple of weeks.



Previously this worked fine.



I.m perplexed at what is going on. It.s not going to the home position, nor the cold start position, yet everything ran fine for the night, until then.



Doug



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 12:02 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob



[Non-text portions of this message have been removed]



---------------

Posted by: "Doug Bock" dbock1@...>

---------------



---------------



Yahoo Groups Links











[Non-text portions of this message have been removed]







---------------

Posted by: "Doug Bock" dbock1@...>

---------------





---------------



Yahoo Groups Links







----------------------------

#59559 Jul 7, 2017

I have the latest G2 and the battery indicator says it.s 100%







From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Friday, July 7, 2017 4:48 AM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.











Fair point ... worth checking the voltage on it anyway.



I assume you have the battery life modification installed if yours is an early G1? www.gemini-2.com/Gemini-1%20mods.php>



The later boards have this change implemented using an SMD resistor.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:58

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



Hmm. I would think that battery would last longer than 9 months.



Doug



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 4:24 PM

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



1st step, replace the memory backup battery.



Dave



-----Original Message-----

From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: 06 July 2017 21:11

To: Losmandy_users@yahoogroups.com

Subject: RE: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



I.ve had something similar, but when SGP tells it to park itself. Instead of going to the home position, it slews until it hits the safety stop to the west.



When I go out to look at it, the scope is pointing about 40 degrees below horizon to the north, and the RA axis is pointing about 15 degrees below horizon to the west. Counter weights high in the east.



This has happened twice during an automation run with SGP parking it at the end of a sequence, the past couple of weeks.



Previously this worked fine.



I.m perplexed at what is going on. It.s not going to the home position, nor the cold start position, yet everything ran fine for the night, until then.



Doug



From: Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Thursday, July 6, 2017 12:02 PM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Re: Gemini pointed the telescope 180 degrees in error upon meridian flip.



Hi Paul,



As I think about where the scope was, it had to be the dec position. I'm using SGP and I have had zero problems with meridian flies up until last night.



Rob



[Non-text portions of this message have been removed]



---------------

Posted by: "Doug Bock" dbock1@...>

---------------



---------------



Yahoo Groups Links



[Non-text portions of this message have been removed]



---------------

Posted by: "Doug Bock" dbock1@...>

---------------



---------------



Yahoo Groups Links











[Non-text portions of this message have been removed]



----------------------------

#59560 Jul 7, 2017

Hi gang,

Gemini1 units can seem to have a split personality on occasion. (I have no Gemini2 to verify the behavior is identical...but suspect it has the same software basis.) .

As David said, measure the internal battery and see that it remains about 3V.. The spec on the SRAM says it should hold its data until external Vcc drops below 2V, .but the Gemini1 uses a diode to select internal battery or external 5V (from external 12-18V), and the diode causes abit a 0.2V drop at the SRAM. ..

When external DC power is supplied to the Gemini1 and switched on, the battery is bypassed.. Only the internal 4.5V ( 5V - diode drop of about 0.5V) appears at the SRAM Vcc. By the SRAM datasheet, the only way a weak battery should lose the SRAM data is if the battery terminal voltage at the SRAM drops below 2V, or the SRAM glitches (known SRAM data errors can arise from "soft errors" from alpha particle penetration into the memory transistor area ). .

To diagnose your pointing error issue:

I suggest you first look at the pointing model values.. You can easily see them using the Gemini.net applet, from your computer connected by serial port to the Gemini.. If the values are very high, it would mean the system is using them to compensate for some other value that is out of whack...perhaps a bad digit in the Latitude or Longitude, .or Date, Time, Elevation, even Mount Type can revert to Titan or be wrong. .

The pointing model can go wrong from a good working model if, say, you still have the checkbox "Synch performs Align" in the Gemini.net applet.. Then, perhaps when you set up for the imaging session, you might have tried to re-Synch the good stored model to your sky chart, and instead threw the Gemini a new data point that it tried to fit with earlier Align data...and this may wreck the stored pointing model.

If the model parameters appear very large or unusual, or you are unsure, I'd do a cold boot, and regenerate the model.

To do your model after the cold boot, it has to be done in the recommended order, else the model parameters can come out weird.. I find that the objects you pick can be chosen from a sky chart (I use Stellarium with Stellarium-scope), and does not require the hand unit object selection of bright stars. .(I have to do this, as my light pollution, trees, and house obstructions prevent my using only the bright star list.) .

The order recommended in the Gemini manual is:

Pick 3 stars on the same side of the meridian...either East or West...don't mix these first 3 stars.. For each, be sure you have done a complete Align step .(the handset will ask you to verify and respond saying it aligned...but using Gemini.net, check the box for "Synch performs additional Align" and then a simple Synch from the Sky chart will accomplish the Align step.)

After these first 3 stars on one side of the Meridian are Aligned, .choose 3 stars on the other side, and Align to them.. You should be done with a good model and your pointing should be accurate. .

At that point, I turn off the checkbox for "Synch performs additional Align" to keep the model from being thrown off.. I do re-Synch as the sky rotates (or is it the Earth?). .

It is worth it to then examine the model values of your (good) sky model.. I'd write them down...they show you at least the order of magnitude of what good model values should look like. .

Hope this may help you. ..

Michael







----------------------------

#59817 Aug 15, 2017

Hi everyone,First of all, I.d like to report that since your help with guiding, the guiding on my G11 has been superb, running close to a half an arc second.��

Another issue has popped up. For weeks, i have had very few problems with meridian flips. I would get everything setup and purring and in the morning, I would get up and everything would have functioned normally with meridian flip happening as it should. In the last three nights that has changed. Two of those nights the meridian flip failed with my telescope pointed to ��the same place at the ground. One night in between those two nights it worked fine. All three nights were shooting the same target. I am using SGPro to guide the camera and the mount. The only thing that I can think of that is different in the three nights is on the night that worked fine, I did a cold start and rebuilt the model. In the past I've been able to use warm restart from CWD position with no problem. My mount during the summer months stays set up in my back yard. Any thoughts on what might be causing this?

Rob



----------------------------

#59821 Aug 15, 2017

Hi.

This,hapoens,can means your T pointing model is messed up.

It happens because of the way the Gemini extracts the model parameters in sequence.. It seems it cannot do a multidimensional least squares fit ...so it gets certain values first, then estimates the next most critical ones. . You must follow the procedure somewhere in the manual, like:

(My uppercase text is not really shouting...I apologize!)

Cold boot (zeros out the pointing model values in the Gemini).

Align to 3 stars on only one side of the meridian.

Align to 3 more stars on the other side if the meridian. .

Your model should be good...next Gotos should be accurate.

--- other things that can get you ------

If you are connected to a PC, use Gemini.net...carefully:

Disconnect the Gemini from the PC, but boot up the Gemini.net applet. Let it say, "not connected."

Un-check the tick box: (something like:) "Send from PC to Gemini on connect". .(Top right tick box on the Advanced screen...I think.)

Now connect the Gemini to the PC.

Read back the Gemini box internal model parameters.. Look at them.. They should be pretty low....not zero but reasonably low. .

Save the model into a backup file on your PC.. Give it a unique name not the default name.. I use like "G11-Gemini1-good-Aug-15-2017" .

Then you can re-check the tick box "Send to Gemini on connect".. Now your time/date/Lat/Long, etc will be sent. .

If you use 2 or more mounts with 1 Gemini, and one laptop, this gets tricky!. Worse if the mounts are different type like G11 vs GM8....(yes...that's my case).. You must be sure your Gemini Settings match the mount... worth double checking.

All the best,Michael.



----------------------------

#59822 Aug 15, 2017

Michael, thanks for your reply. As you said there may be issues in connecting to a PC, I thought I would describe the way I am currently building a model after doing a cold restart. I launch Gemini. Net in SGPro. In SGPro I have set up a sequence with six stars, three on the west and three on the east. When I start the sequence, it automatically slews to the stars and centers them precisely. On Gemini.net I bring up the function that allows me to additionally align and find the current star that SGPto is has centered and click addional alignment. I do this for all six stars. The go to funci.n on Gemini.net is nearly perfect after I do this. I don't think this is causing a problem because the one night in the three I did this there was no problem with meridian flip. But if you think otherwise, please let me know.

Rob



----------------------------

#59823 Aug 15, 2017

Gosh, Rob!

I have had the same experience as you have... load a "known good model" and ... very weird... the mount will slew to point my scope to the floor while I wonder what button to push to stop it!

I don't know why the system would do this, but there are many possible causes.. Any of the wrong values of time/date/longitude... that data could be corrupt.. Another reason is that the pointing model has something totally whacked out. .

The thing that has worked for me to recover normal operation is to completely zero out the T model parameters. .

Does your Cold Boot send you into limbo?. Then it must be a wrong UT, latitude, longitude, date, time.. The zero model values should still get you relatively close to your first alignment star (maybe an hour off in RA if the Daylight Savings time correction gets it wrong.)

Then I do what you do too: I use Stellarium (with Stellarium-scope) to pick my 3 stars on each side of the meridian.. I don't usually use the hand controller list except for perhaps the very first very bright star, because I don't know what will be on that list, and my house surroundings limit my sky view.. I am limited to mostly overhead and about 90 degrees E-W region and 120 degrees N-S.. So I must pick my alignment stars from a sky chart. .

Like I said, I found it too easy for the PC to send in its default model parameters and mess me up.. Be careful that is not happening to your system. .

Now you have a "bad" sky model in your Gemini.. That has a value..it has clues to the problem.. Read those values back into a file...maybe write them down too.. Then try to make a new good model that is working well.. Compare the model values and try to figure out what might be a bad value. .

All we can say for sure is that it is certainly a Gemini problem... the question is what setting has gone bad.



Can it be hardware/electronics and not a model value?

There have been sparse reports that an EPROM chip in the Gemini-1 has gone bad.. Though I never would have believed it, I have measured some of these chips to go bad.. Usually it is one bit gone bad, but many can also go wrong. . In that case, the firmware is corrupt and the part should be replaced.. I have now bought an EPROM eraser and can test and reprogram these chips for anyone with a questionable one....or I have new ones too ready to send to anyone (the last version Level 4 v1.05). .

Can an SRAM go bad?

Yes... but the Gemini-1 is supposed to test the SRAM for validity...and show a dot and not boot up if that SRAM is bad.. If the system boots, it is likely the SRAM is OK. .(and I have replaced a bad SRAM for one unit...). .

Can an SRAM glitch?That's an open question.. The T-model values inside the Gemini-1 are held in SRAM which is powered by the 3V battery.. That battery circuit has a Schottky diode after the battery, so the voltage coming off the Schottky diode is about 2.8V to the SRAM.. Likewise the voltage after powerup with DC external applied (12V-18V) comes thru a 5V regulator, so after that goes through its Schottky diode, only about 4.7V comes out to the SRAM. .



The SRAM itself does not care as long as its Vcc is over 2V, it should hold its data.. But the pins of the SRAM are getting the full 5V from the other chips (and microprocessor) that it talks to, and the spec on the SRAM is that its pins should not see more than 0.5V difference... not more than 0.5V over its Vcc, or 0.5V below ground...else the pin can get damaged.. I think (without proof) that this is why some SRAM chips go bad yearly, for someone in our group. .

-All the best, and when you find the culprit, let us know!!!

Michael





On Tue, Aug 15, 2017 at 12:02 PM, sactowriter@... [Losmandy_users] Losmandy_users@yahoogroups. com> wrote:

.Michael, thanks for your reply. As you said there may be issues in connecting to a PC, I thought I would describe the way I am currently building a model after doing a cold restart. I launch Gemini. Net in SGPro. In SGPro I have set up a sequence with six stars, three on the west and three on the east. When I start the sequence, it automatically slews to the stars and centers them precisely. On Gemini.net I bring up the function that allows me to additionally align and find the current star that SGPto is has centered and click addional alignment. I do this for all six stars. The go to funci.n on Gemini.net is nearly perfect after I do this. I don't think this is causing a problem because the one night in the three I did this there was no problem with meridian flip. But if you think otherwise, please let me know.

Rob







----------------------------

#60397 Nov 18, 2017

Hi!

Here I am again with a new question (I am soo happy that my previous "not performing Go To Bright Star" was solved!!!):

I'm trying to improve mu guiding (of course). So I'm experimenting a lot with PHD2, that is what I use for guiding. Now this is some results from an experiment yesterday:

I point the scope to the meridian, close to the equator, and run the guiding assistant. After some 3 minutes, it tells me the polar alignment error is 0.3 arc-min (farily ok, I'd say).

Then I do a meridian flip. Point again to the meridian (that is, slewing slightly to the east to compensate for the drift that now has occurred) . Run the guiding assistant again. This time it reports a polar alignment error of 16.3 arc min.

So: what might be going on here? If I trust PHD2, something must be shifting. But what on earth could that be? I mean, flex in the guidescope could not possible cause this, right? It must be something with the mount in that case - or am I wrong? Any suggestions on what to look for and further explore is welcome.

And yes, this is reflected in poorer guiding after meridian flip. Interestingly enough, guiding improves after recalibration, which again feels like a mystery. How could calibration be affected by MF, except DEC switching direction (and then it would go off wildly, which is not what happens - just some 50 % more RMS).

Best,

Magnus



----------------------------

#60400 Nov 18, 2017

Isn���t this a text book definition of ���ConeError���?? ��Not that I know anything about it.. ��Derek ��

From:Losmandy_users@yahoogroups.com [mailto:Losmandy_users@yahoogroups.com]

Sent: Saturday, November 18, 20171:41 AM

To: Losmandy_users@yahoogroups.com

Subject: [Losmandy_users] Polaralignment shifts after meridian flip

���� Hi!



Here I am again with a new question (I am soo happy that my previous "notperforming Go To Bright Star" was solved!!!):



I'm trying to improve mu guiding (of course). So I'm experimenting a lot withPHD2, that is what I use for guiding. Now this is some results from anexperiment yesterday:



I point the scope to the meridian, close to the equator, and run the guidingassistant. After some 3 minutes, it tells me the polar alignment error is 0.3arc-min (farily ok, I'd say).



Then I do a meridian flip. Point again to the meridian (that is, slewingslightly to the east to compensate for the drift that now has occurred) . Runthe guiding assistant again. This time it reports a polar alignment error of16.3 arc min.



So: what might be going on here? If I trust PHD2, something must be shifting.But what on earth could that be? I mean, flex in the guidescope could notpossible cause this, right? It must be something with the mount in that case -or am I wrong? Any suggestions on what to look for and further explore iswelcome.



And yes, this is reflected in poorer guiding after meridian flip. Interestinglyenough, guiding improves after recalibration, which again feels like a mystery.How could calibration be affected by MF, except DEC switching direction (andthen it would go off wildly, which is not what happens - just some 50 % moreRMS).



Best,



Magnus ��

�� Virus-free.www.avg.com



----------------------------

#60402 Nov 20, 2017

Hi!

Isn't cone error something else? That does not "affect" polar alignment, but causes field rotation and similar problems. I mean, polar alignment and drift alignment depends on the mount, not on how the scope is mounted on the mount. Or am I wrong?

Magnus



----------------------------

#60403 Nov 20, 2017

At 21:17 20-11-17,

jfev5mnsvqiyzpq756wvokt55jve7sbg2esr5mip@... [Losmandy_us wrote:

>Isn't cone error something else? That does not

>"affect" polar alignment, but causes field

>rotation and similar problems. I mean, polar

>alignment and drift alignment depends on the

>mount, not on how the scope is mounted on the mount. Or am I wrong?



Cone error is when the axis of the OTA is not

parallel to the RA axis. Then, even though the

mount is accurately polar aligned, the OTA

describes a cone around the projection of the

polar axis. Easy to visualise by imagining that a

refractor is at a 45. angle to the RA axis. Then

as the axis turns the OTA will also turn and will

always be pointing somewhere else other than the NCP.



I am not sure that this explains your problem however.

>But what on earth could that be? I mean, flex in

>the guidescope could not possible cause this, right?



If the guidescope is leaning one way before the

flip and its mounting is loose enough to make it

lean the other way afterwards, I should have

thought it quite possible that this is the reason

for your problem. At all events, I think that

_something_ is moving as the flip happens.



David



----------------------------

#60404 Nov 20, 2017

For an object at the celestial equator, I don.t think cone error will have any first-order impact on guiding. It shouldn.t lead to the drift in declination that Magnus is seeing. This also means that drift alignment should not be affected by cone error.



-Les





> On 20 Nov 2017, at 12:34, David Pickett yahoo@... [Losmandy_users] Losmandy_users@yahoogroups.com> wrote:

>

> At 21:17 20-11-17,

> jfev5mnsvqiyzpq756wvokt55jve7sbg2esr5mip@... [Losmandy_us wrote:

>

>> Isn't cone error something else? That does not

>> "affect" polar alignment, but causes field

>> rotation and similar problems. I mean, polar

>> alignment and drift alignment depends on the

>> mount, not on how the scope is mounted on the mount. Or am I wrong?

>

> Cone error is when the axis of the OTA is not

> parallel to the RA axis. Then, even though the

> mount is accurately polar aligned, the OTA

> describes a cone around the projection of the

> polar axis. Easy to visualise by imagining that a

> refractor is at a 45. angle to the RA axis. Then

> as the axis turns the OTA will also turn and will

> always be pointing somewhere else other than the NCP.

>

> I am not sure that this explains your problem however.

>

>> But what on earth could that be? I mean, flex in

>> the guidescope could not possible cause this, right?

>

> If the guidescope is leaning one way before the

> flip and its mounting is loose enough to make it

> lean the other way afterwards, I should have

> thought it quite possible that this is the reason

> for your problem. At all events, I think that

> _something_ is moving as the flip happens.

>

> David

>

>

>

---------------

> Posted by: David Pickett yahoo@...>

---------------

>

>

---------------

>

> Yahoo Groups Links

>

>

>

>







[Non-text portions of this message have been removed]







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