Re: Software wish list

Ladislav Nemec <nemecl@...>

It's late even here in CA and I made my first attempt to use the 'meridian
delay' method with my Losmandy/Gemini G11. The Gemini Level 4 does what it
calls 'meridian flip', i.e. for stars close enough to the meridian, it moves
from east to west (and vice versa) when it determines that the move is safe
(based on stored east-west motion limits of the mount).

It kind of worked except for my difficulties to look into the finder and/or
eyepiece in one position of the flip. I'll try again using my camera to
center the star with (first) elevation adjustment and then with a pair of
stars at similar RA for azimuth adjustment. Bit too old to crawl under the
scope to look through the eyepieces.

AP manual I accessed through the links below (I think - I do not remember
recent details any longer.) has an excellent explanation of the method and
very handy list of star pairs for the azimuth adjustment.

In the meantime, I used my favorite old polar alignment method of LX200
mount with an equatorial edge: sync on a star close to meridian at moderate
DEC, move to Polaris, adjust using elevation and azimuth knobs. Back to the
previous star, center it, sync it. Back to Polaris, and so on. Two to five
iterations yield fairly good polar alignment with ANY equatorial mount.

Currently, I am recording hours of tracking errors superimposed over RA and
Dec 'drift' using PemPro. The Dec 'drift' (result of imperfect polar
alignment) is usually pretty monotonous, mostly a straight line. RA 'drift',
however, is rather bumpy because, I believe, imperfections of the RA gear
(sidereal 24 hour gear). Good to know where the 'sweet' spots of your RA
gear are.

Probably a non-issue for AP mount owners, sorry for even mentioning it here.

Thanks for your comments but I believe I am on the right track.

Gemini calls pointing to the same object from the other side a 'Meridian
flip' - I think it is equivalent to somewhat more involved 'meridian delay'
mentioned in the AP manual.


Ladislav Nemec

Big Bear, CA

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of
Chris Curran
Sent: Friday, September 12, 2008 3:09 AM
To: ap-gto@...
Subject: [ap-gto] Re: Software wish list


"Meridian Flip" typically means something else - usually you're
telling the software that your scope has moved from one side of the
mount to the other for guiding purposes. When I "flip" sides, I
recalibrate so I never use this feature.

I'm guessing that if your GOTO mount calculates and uses LST, you
could adjust the LST in your mount and use the MD method. I've also
got an EM-200 mount that I never did figure out how to use the MD
method with - there's no time setting.

If you figure something please out let us know...

cheers & beers,

--- In ap-gto@yahoogroups. <> com, "Ladislav
Nemec" <nemecl@...> wrote:

One should, indeed, do his quick search before asking a question
here. It
appears that the method described in detail in one of the AP manuals
can be
used for Gemini Level 4. I never tried that but, apparently, as long
as the
same object can be reached from both east and west from meridian, a
'Meridian Flip' appears on the Gemini Quick Menu. Actually simpler than
described in the AP manual. In about 5 hours I'll try that.

Again, my apologies for being off-topic here but Rolando certainly
gives a
good advice, not only to AP users.



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