G11 clutch spacer question.
The old G11 Celestron model I recently got may be missing some parts. Both clutch assemblies have the following: knob - spring washer - thin washer - thrust bearing...and that's all. Isn't there supposed to be a spacer and another thin washer? Haven't tried a load on the mount yet. I am just in the process of disassembly for cleaning.
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Yes. ?I have used the sti on my CG11 using ccdops and ccdsoft software. ?Works great ??..
toggle quoted message
Show quoted text
On Nov 9, 2017, at 8:06 PM, puzzlewuzzle.dr@... [Losmandy_users] < Losmandy_users@...> wrote:
?
Will the SBIG ST-i interface with the Losmandy G-11 492 system of Celestron era? I recently picked up such a G-11 and I happen to have a ST-i. Thanks for any advice. David
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Will the SBIG ST-i interface with the Losmandy G-11 492 system of Celestron era? I recently picked up such a G-11 and I happen to have a ST-i. Thanks for any advice. David
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Re: GM8 DEC axis head... depth of blind holes for attaching saddle...
Hi Bill,
Consider this upgrade carefully. The GM8's saddle may have been kept as short as possible for at least two reasons I can see.?
First, mechanical clearance of the saddle. The standard Losmandy D and later D/V saddle's short overall length allow more RA travel before hitting the safety limiter when you consider the rotation of the DEC axis than if you had a longer wider saddle or a saddle with a taller clamping knob or clamping lever. For an imager this may be more important than a nicer saddle. Second,?the mount doesn't need more clamping surface area as the standard/DV saddle can probably safely carry double the rated 30lb. payload.?
Additionally the 30lb. payload limitation of the GM8 mount precludes the need to hoist heavy OTAs into the saddle. For the cost of a Raynox saddle even as pretty as it is for about the same money I'd rather have Scott install the tucked motors on my GM8 AND add a pair of the new OPWs.?Just stating the obvious issues I see I'm certain there are other reasons I'm not aware of.?
Cheers/Chip
?
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Re: GM8 DEC axis head... depth of blind holes for attaching saddle...
I wonder if that upgrade has primarily been purchased by G11 owners? ? ? ? Thanks ? Brian ? ? Brian Valente Brianvalentephotography.com ?
toggle quoted message
Show quoted text
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Thursday, November 9, 2017 10:30 AM
To: Losmandy_users@...
Subject: [Losmandy_users] GM8 DEC axis head... depth of blind holes for attaching saddle...? ? Folks, ? Replacing the stock "short" Losmandy saddle on my GM811 with one of Stephen Pizzo's RAYOX saddles. ? The stock Losmandy saddle is mounted with two 1/4-20 socket head screws that extend 7/32" beneath the saddle and screw into the two tapped blind holes in the DEC axis head.?? ? Stephen supplies machine screws for mounting that extend 10/32" beneath the mounting plate and screw into the same holes.? They were too long and I couldn't snug the mounting plate down. ? Simple solution, just use shorter machine screws.? Yes, but since this ultimately is what holds the whole saddle/OTA onto the DEC axis, one wants to make sure it is solidly mounted. ? Stephen was a little surprised in that he hadn't had the issue raised before.? I contacted Losmandy and was told that nothing has really changed with those mounting holes for the saddle on a GM811 or GM8. ? I measured the depth of those blind holes and I get 9/32".? Or at least I know I engage 9/32" of thread before any screw bottoms out. ? Wondering, others out there with GM811 or GM8s, could you measure the depth of those blind holes for mounting the saddle and what do you get? ? Thanks... ? ... Bill
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GM8 DEC axis head... depth of blind holes for attaching saddle...
Folks,
Replacing the stock "short" Losmandy saddle on my GM811 with one of Stephen Pizzo's RAYOX saddles.
The stock Losmandy saddle is mounted with two 1/4-20 socket head screws that extend 7/32" beneath the saddle and screw into the two tapped blind holes in the DEC axis head.??
Stephen supplies machine screws for mounting that extend 10/32" beneath the mounting plate and screw into the same holes.? They were too long and I couldn't snug the mounting plate down.
Simple solution, just use shorter machine screws.? Yes, but since this ultimately is what holds the whole saddle/OTA onto the DEC axis, one wants to make sure it is solidly mounted.
Stephen was a little surprised in that he hadn't had the issue raised before.? I contacted Losmandy and was told that nothing has really changed with those mounting holes for the saddle on a GM811 or GM8.
I measured the depth of those blind holes and I get 9/32".? Or at least I know I engage 9/32" of thread before any screw bottoms out.
Wondering, others out there with GM811 or GM8s, could you measure the depth of those blind holes for mounting the saddle and what do you get?
Thanks...
... Bill
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Re: RA rate drift (revisited)
>Your guess might be right that with "Gemini calculates refraction" turned off, there could be a difference?> between zenith, say, and East or West directions.??
Gemini Calculates Refraction setting has to do with goto precision and not with tracking. That setting simply tells Gemini to adjust the goto coordinates for the effects of refraction. It does not alter tracking rate or drift.
Regards,
? -Paul
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Re: Leveling the Mount - I don't see the importance
Yep, pointless. There have been 1,243 posts made on this forum over the years about this subject (I counted them...)? and I believe the consensus agrees with my personal findings? - tracking error log shows no difference attributable to the difference between "reasonably" level mount and a "precisely" leveled mount. Search and you will see . Do what you want if it makes you feel better
-Jeff
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Re: RA rate drift (revisited)
Hi Ray,
Your guess might be right that with "Gemini calculates refraction" turned off, there could be a difference between zenith, say, and East or West directions.??
Comparing E and W at the same angle from zenith ...I'd think the rate would be the same...? it is a puzzle...only the original poster can say if the issue is solved.?
Michael
On Nov 6, 2017 7:41 AM, "'Ray Gralak (Groups)' groups3@... [Losmandy_users]" < Losmandy_users@...> wrote:
?
Hi Michael,
> I wonder though...did the original question about mount tracking too fast and too slow in East and West...did that
> puzzle ever get solved?
I am not sure it has been solved. However, without tracking rate correction a mount will always appear to be tracking slightly fast when it is tracking at perfect sidereal rate and perfectly polar aligned and has no flexure.
That's because at the horizon about 30 arc-minutes of sky below the actual physical horizon can be seen because of refraction. Refraction "compresses" the amount of sky that can be seen so normal sidereal rate appears faster than it is, except right at the zenith.
I haven't been following the whole thread but looking back the original poster (Keith) said the star appeared to track fast on the East, but when he flipped the mount the direction of the drift was in the "opposite direction". This is ambiguous as it could be the result of the camera being flipped, so it could still be from refraction. It could also be from the dynamic changes to mount flexure that can occur as pointing angle changes.
Best regards,
-Ray Gralak
Author of APCC (Astro-Physics Command Center):
Author of PEMPro:
Author of Astro-Physics V2 ASCOM Driver:
Author of PulseGuide:
Author of Sigma:
> -----Original Message-----
> From: Losmandy_users@... [mailto: Losmandy_users@yahoogroups.com]
> Sent: Monday, November 6, 2017 6:49 AM
> To: Losmandy_users@...
> Subject: RE: [Losmandy_users] Re: RA rate drift (revisited)
>
>
>
> Hi Ray,
>
> Thanks for that ...I did understand that but....
>
> I somehow missed the statement that the first step: get AZ correct by the drift method, while pointed at Meridian
> and Equator, must already be accomplished.
>
> Then I understand adjusting ELevation at the zenith...as long as AZ is right the only remaining error must be EL.
>
> I like that idea and will try it, since my East and West are totally obstructed.
>
> Sorry for my mis-reading.
>
> -----
>
> I wonder though...did the original question about mount tracking too fast and too slow in East and West...did that
> puzzle ever get solved?
>
> Best,
> Michael
>
>
>
> On Nov 6, 2017 5:05 AM, "'Ray Gralak (Groups)' groups3@... [Losmandy_users]"
> < Losmandy_users@yahoogroups.com Losmandy_users@ yahoogroups.com> > wrote:
>
>
>
>
>
> > When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift),
> > as that tool says in its instructions.
>
> Yes, but as Greg said, this technique is different in that it uses RA drift at the zenith to adjust Altitude polar
> alignment instead of standard Dec drift in the East or West.
>
> There are advantages and disadvantages to this method, but the intent is to null out RA (and Dec) drift
> near the meridian, which is where usually the best quality images can be obtained.
>
> -Ray Gralak
> Author of APCC (Astro-Physics Command Center):
> <
> >
> Author of PEMPro:
> Author of Astro-Physics V2 ASCOM Driver:
> Author of PulseGuide:
> Author of Sigma:
>
> > -----Original Message-----
> > From: Losmandy_users@... [mailto: Losmandy_users@yahoogroups.com
> Losmandy_users@ yahoogroups.com> ]
> > Sent: Sunday, November 5, 2017 1:16 PM
> > To: Losmandy_users@...
> > Subject: Re: [Losmandy_users] Re: RA rate drift (revisited)
> >
> >
> >
> > Hi Greg,
> >
> > Thanks for the notes.
> >
> > When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool
> says in its
> > instructions.
> >
> > [ repeat these 2 steps...
> >
> > When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
> >
> > When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with
> the AZ
> > knob.
> >
> > ]
> >
> > Repeat...[...] til you are satisfied.
> >
> > You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by
> PHD2
> > anyway).
> >
> > Best,
> > Michael
> >
> > On Nov 5, 2017 1:03 PM, " beneckerus@... [Losmandy_users]"
> < Losmandy_users@yahoogroups.com Losmandy_users@ yahoogroups.com> >
> > wrote:
> >
> >
> >
> >
> >
> >
> > This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was
> > discussed. PHD2 displays both the DEC and RA drift in the Drift Alignment tool. So instead of letting
> PHD2 slew
> > the scope to the East for the altitude adjustment, slew it manually to the zenith. Turn on your mount's
> PEC to
> > minimize RA motion. Run the drift session for a full worm cycle to cancel out the effects of the remaining
> PE.
> > Adjust the altitude to minimize the RA drift. There is no point in doing the Eastern altitude adjustment first
> as this
> > will always change for the minimum RA drift adjustment.
> >
> > I found it interesting to think about this at the limit of doing polar alignment at the equator, where the
> > intersection of the celestial equator and the meridian is also the zenith. Using this method there you
> would not
> > move the scope from the zenith for either adjustment
> >
> > Greg
> >
> >
> >
>
>
>
>
|
Re: RA rate drift (revisited)
Hi Michael, I wonder though...did the original question about mount tracking too fast and too slow in East and West...did that
puzzle ever get solved? I am not sure it has been solved. However, without tracking rate correction a mount will always appear to be tracking slightly fast when it is tracking at perfect sidereal rate and perfectly polar aligned and has no flexure. That's because at the horizon about 30 arc-minutes of sky below the actual physical horizon can be seen because of refraction. Refraction "compresses" the amount of sky that can be seen so normal sidereal rate appears faster than it is, except right at the zenith. I haven't been following the whole thread but looking back the original poster (Keith) said the star appeared to track fast on the East, but when he flipped the mount the direction of the drift was in the "opposite direction". This is ambiguous as it could be the result of the camera being flipped, so it could still be from refraction. It could also be from the dynamic changes to mount flexure that can occur as pointing angle changes. Best regards, -Ray Gralak Author of APCC (Astro-Physics Command Center): Author of PEMPro: Author of Astro-Physics V2 ASCOM Driver: Author of PulseGuide: Author of Sigma: -----Original Message-----
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Monday, November 6, 2017 6:49 AM
To: Losmandy_users@...
Subject: RE: [Losmandy_users] Re: RA rate drift (revisited)
Hi Ray,
Thanks for that ...I did understand that but....
I somehow missed the statement that the first step: get AZ correct by the drift method, while pointed at Meridian
and Equator, must already be accomplished.
Then I understand adjusting ELevation at the zenith...as long as AZ is right the only remaining error must be EL.
I like that idea and will try it, since my East and West are totally obstructed.
Sorry for my mis-reading.
-----
I wonder though...did the original question about mount tracking too fast and too slow in East and West...did that
puzzle ever get solved?
Best,
Michael
On Nov 6, 2017 5:05 AM, "'Ray Gralak (Groups)' groups3@... [Losmandy_users]"
<Losmandy_users@... <mailto:Losmandy_users@...> > wrote:
> When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift),
> as that tool says in its instructions.
Yes, but as Greg said, this technique is different in that it uses RA drift at the zenith to adjust Altitude polar
alignment instead of standard Dec drift in the East or West.
There are advantages and disadvantages to this method, but the intent is to null out RA (and Dec) drift
near the meridian, which is where usually the best quality images can be obtained.
-Ray Gralak
Author of APCC (Astro-Physics Command Center):
physics.com/index.htm?products/accessories/software/apcc/apcc <
physics.com/index.htm?products/accessories/software/apcc/apcc>
Author of PEMPro:
Author of Astro-Physics V2 ASCOM Driver:
Author of PulseGuide:
Author of Sigma:
> -----Original Message-----
> From: Losmandy_users@... [mailto:Losmandy_users@...
<mailto:Losmandy_users@...> ]
> Sent: Sunday, November 5, 2017 1:16 PM
> To: Losmandy_users@...
> Subject: Re: [Losmandy_users] Re: RA rate drift (revisited)
>
>
>
> Hi Greg,
>
> Thanks for the notes.
>
> When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool
says in its
> instructions.
>
> [ repeat these 2 steps...
>
> When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
>
> When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with
the AZ
> knob.
>
> ]
>
> Repeat...[...] til you are satisfied.
>
> You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by
PHD2
> anyway).
>
> Best,
> Michael
>
> On Nov 5, 2017 1:03 PM, "beneckerus@... [Losmandy_users]"
<Losmandy_users@... <mailto:Losmandy_users@...> >
> wrote:
>
>
>
>
>
>
> This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was
> discussed. PHD2 displays both the DEC and RA drift in the Drift Alignment tool. So instead of letting
PHD2 slew
> the scope to the East for the altitude adjustment, slew it manually to the zenith. Turn on your mount's
PEC to
> minimize RA motion. Run the drift session for a full worm cycle to cancel out the effects of the remaining
PE.
> Adjust the altitude to minimize the RA drift. There is no point in doing the Eastern altitude adjustment first
as this
> will always change for the minimum RA drift adjustment.
>
> I found it interesting to think about this at the limit of doing polar alignment at the equator, where the
> intersection of the celestial equator and the meridian is also the zenith. Using this method there you
would not
> move the scope from the zenith for either adjustment
>
> Greg
>
>
>
|
Re: RA rate drift (revisited)
Hi Ray,
Thanks for that ...I did understand that but....
I somehow missed the statement that the first step:? get AZ correct by the drift method, while pointed at Meridian and Equator, must already be accomplished.?
Then I understand adjusting ELevation at the zenith...as long as AZ is right the only remaining error must be EL.??
I like that idea and will try it, since my East and West are totally obstructed.
Sorry for my mis-reading.
-----
I wonder though...did the original question about mount tracking too fast and too slow in East and West...did that puzzle ever get solved?
Best, Michael?
?
> When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift),
> as that tool says in its instructions.
Yes, but as Greg said, this technique is different in that it uses RA drift at the zenith to adjust Altitude polar alignment instead of standard Dec drift in the East or West.
There are advantages and disadvantages to this method, but the intent is to null out RA (and Dec) drift near the meridian, which is where usually the best quality images can be obtained.
-Ray Gralak
Author of APCC (Astro-Physics Command Center):
Author of PEMPro:
Author of Astro-Physics V2 ASCOM Driver:
Author of PulseGuide:
Author of Sigma:
> -----Original Message-----
> From: Losmandy_users@... [mailto:Losmandy_users@yahoogroups.com]
> Sent: Sunday, November 5, 2017 1:16 PM
> To: Losmandy_users@...
> Subject: Re: [Losmandy_users] Re: RA rate drift (revisited)
>
>
>
> Hi Greg,
>
> Thanks for the notes.
>
> When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool says in its
> instructions.
>
> [ repeat these 2 steps...
>
> When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
>
> When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with the AZ
> knob.
>
> ]
>
> Repeat...[...] til you are satisfied.
>
> You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by PHD2
> anyway).
>
> Best,
> Michael
>
> On Nov 5, 2017 1:03 PM, "beneckerus@... [Losmandy_users]" <Losmandy_users@yahoogroups.com>
> wrote:
>
>
>
>
>
>
> This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was
> discussed. PHD2 displays both the DEC and RA drift in the Drift Alignment tool. So instead of letting PHD2 slew
> the scope to the East for the altitude adjustment, slew it manually to the zenith. Turn on your mount's PEC to
> minimize RA motion. Run the drift session for a full worm cycle to cancel out the effects of the remaining PE.
> Adjust the altitude to minimize the RA drift. There is no point in doing the Eastern altitude adjustment first as this
> will always change for the minimum RA drift adjustment.
>
> I found it interesting to think about this at the limit of doing polar alignment at the equator, where the
> intersection of the celestial equator and the meridian is also the zenith. Using this method there you would not
> move the scope from the zenith for either adjustment
>
> Greg
>
>
>
|
Re: RA rate drift (revisited)
When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift),
as that tool says in its instructions. Yes, but as Greg said, this technique is different in that it uses RA drift at the zenith to adjust Altitude polar alignment instead of standard Dec drift in the East or West. There are advantages and disadvantages to this method, but the intent is to null out RA (and Dec) drift near the meridian, which is where usually the best quality images can be obtained. -Ray Gralak Author of APCC (Astro-Physics Command Center): Author of PEMPro: Author of Astro-Physics V2 ASCOM Driver: Author of PulseGuide: Author of Sigma: -----Original Message-----
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Sunday, November 5, 2017 1:16 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: RA rate drift (revisited)
Hi Greg,
Thanks for the notes.
When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool says in its
instructions.
[ repeat these 2 steps...
When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with the AZ
knob.
]
Repeat...[...] til you are satisfied.
You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by PHD2
anyway).
Best,
Michael
On Nov 5, 2017 1:03 PM, "beneckerus@... [Losmandy_users]" <Losmandy_users@...>
wrote:
This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was
discussed. PHD2 displays both the DEC and RA drift in the Drift Alignment tool. So instead of letting PHD2 slew
the scope to the East for the altitude adjustment, slew it manually to the zenith. Turn on your mount's PEC to
minimize RA motion. Run the drift session for a full worm cycle to cancel out the effects of the remaining PE.
Adjust the altitude to minimize the RA drift. There is no point in doing the Eastern altitude adjustment first as this
will always change for the minimum RA drift adjustment.
I found it interesting to think about this at the limit of doing polar alignment at the equator, where the
intersection of the celestial equator and the meridian is also the zenith. Using this method there you would not
move the scope from the zenith for either adjustment
Greg
|
Re: Power supply needed on pier.
My mount is the G11-G.??
I beleive I can manage my power needs with a 10a supply.? Just to have a little extra.? ?
Les, thanks for the link for the Canon switching regulator.??
Thanks for your responses, I am now closer to achieving a better pier set-up
Thomas Glynn Springfield, MO??
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Re: Leveling the Mount - I don't see the importance
Pointless?? I would disagree if you wanted the best tracking you could achieve.? Three factors play into the alignment:
1:? Has the polar-scope been calibrated to the mount?? If not the mount is correcting for misalignment between what it sees as NCP and where the mount is actually pointing.
2: Has the cone error been corrected between the NCP and the view in the telescope? Wouldn't it be better if the telescope and the polar scope point at exactly the same point.
3: Did the mount start out at the magical CWD position?? This is a perfectly leveled mount in RA and DEC.? Are these setting repeatable each time setup is conducted?? You can mark the setting circles once this has been established not a time consuming action each time.? Also note where the leveling bubble is after these three are completed and use this position next time you set up. If the mount is not level then CWD is not repeatable.
So when you set up, if the three factors are established, just leveling the mount puts you the best tracking position.? Why make the mount correct in Dec and RA when you can just let RA do most of the work?? ?
I roll my set up out and place in the same position each time.? I level the mount, plug in the power and my 3,0 usb cable and turn on My polemaster. I then run my QHY Polemaster program to establish polar alignment and I'm off to imaging after aligning with the SkyX. I can do a bright star alignment or three on each side or have The SkyX do a T point run.? Usually after one star the mount is dead on because it builds on what it did the last time.??
IMHO.? I take leveling serious. And it doesn't take that long, and is easier when it is daylight.??
Thomas Glynn Springfield, MO Losmandy G11-G?
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Re: Leveling the Mount - I don't see the importance
Thanks to all for your comments on this issue.? I believe it is clear that having a precisely level mount does not preclude an accurate polar alignment or accurate GOTO performance.? ?Certainly, as Chip pointed out, it is more critical on Alt-Az mounts but this group is all about equatorial mounts. Thanks, Dave...
|
Re: G1 on G-11 refuses to go to bright stars
Magnus
IMHO "interrupted" can only come from one of four things:
A): A handset Ra/Dec button was activated during slew (either by touch or electronic failure, aka a momentary short cct);
or
B):Something is wrong with the way the system computes commands and is causing slew failures yet the system does not think there is an error!? Something like EPROM data.
or
C): Maybe you are correct pointing error model?
or
D): External issue such as RS232 causing or issuing a command during slew.
Failure A): Most likely its not this as the issue occurs during goto slews not park slews etc.
Failure B): This is possible.? Do you have your old EPROM? Can you R&R it back in?
Failure C): Its possible.? You may need to completely reset the Gemini data and start again, maybe don't do a point model yet just do cold start and re-input appropriate data then try some goto's.
Failure D): Its possible, ensure anything RS232 is removed and test.
This is about all I know on this.? I really do not think its an electronic issue requiring multimeter probing however I can supply info on where to test if you want to look at this....just in case.? Please say if you want to pursue this avenue.
A bad EPROM is possible and well we wouldn't know until replaced.?? I can send you a lvl 1.04 or 1.05 to try if you want.? I'm happy to...all free...just want to assist as best I can as this is nagging me so it must be really peeeving you off!
As for point model errors or corruption.? This is quite a possibility.? The only way to tell is to dump the current re-set Gemini and test without a model.
Well that's all I can think of.? Of course a sweet Gemini 2 might be starting to look favourable.? Maybe ask Losmandy for upgrade cost?
Tell us how you want to proceed
regards
Brendan?
|
Re: Leveling the Mount - I don't see the importance
For a GEM, once the computer is aligned leveling the mount or tripod makes no difference for GOTOs operation. But a mechanically plumb tripod or pier is more stable, settles faster and your elevation and azimuth mount alignment controls will make true movements not diagonal which makes polar alignment easier to nail more quickly.
For an Alt/Az mount leveling the mount is typically fairly important for single star GOTO performance unless you are going to shoot multiple stars to build a model to compensate for the mount's leveling error but even then a level and plumb mount will work better.
Chip
|
Re: RA rate drift (revisited)
Hi Greg,
Thanks for the notes.??
When using the PHD2 drift tool, it is only the DEC drift you want to null out (not RA drift), as that tool says in its instructions.
[ repeat these 2 steps...
When you are pointing first near meridian and celestial equator, only adjust the AZ knobs.
When pointing next, as far East or West as possible, then again look only at DEC drift, and null out with the AZ knob.??
]
Repeat...[...] til you are satisfied.
You really don't need to bother about the PEC... you can ignore errors in that for the drift alignment (by PHD2 anyway).
Best, Michael?
On Nov 5, 2017 1:03 PM, " beneckerus@... [Losmandy_users]" < Losmandy_users@...> wrote:
?
This subject is a current topic on the Astro-Physics group (#59424) and the subject of using PHD2 was discussed.? PHD2 displays both the DEC and RA drift in the Drift Alignment tool.? So instead of letting PHD2 slew the scope to the East for the altitude adjustment, slew it manually to the zenith.? Turn on your mount's PEC to minimize RA motion.? Run the drift session for a full worm cycle to cancel out the effects of the remaining PE.? Adjust the altitude to minimize the RA drift.? There is no? point in doing the Eastern altitude adjustment first as this will always change for the minimum RA drift adjustment.
I found it interesting to think about this at the limit of doing polar alignment at the equator, where the intersection of the celestial equator and the meridian is also the zenith.? Using this method there you would not move the scope from the zenith for either adjustment
Greg
|
Bill Krosney
Paul Kanevsky
photon_trap
Michael Herman
David Cochrun