Re: [APML] Drift alignment problem - wedge mounted scope

["Bradley" <bhope@thorngarden.net>]

I doubt mirror flop would be an issue in this instance for two reasons. The
mirror is locked, and the scope is only moving ~20 degrees, from ~+30
degrees elevation to ~+50 degrees elevation above the Southern horizon.
However, I won't rule out any possible cause at this point.

Gene, fortunately MAPUG set up a forwarding url to the new server and I was
able to find it. Applied and replied to the confirmation request, but
haven't yet received the final confirmation.

Richard, the only RA drift I'm seeing is a result of two factors; the
tracking rate not being perfectly Sidereal, and from periodic error.

I started an experiment last night and drift aligned at 0 degrees
declination and was then going to check at +10 and -10 degrees to see if it
showed declination drift in different directions (I suspect it will based on
what I'm seeing at this point)...but had a nice, thick layer of low clouds
move in just as I finished the initial alignment. I was aligned at -10
degrees declination and did have to adjust azimuth to eliminate dec drift at
0 degrees.

Steve, I'll be certain to post a follow-up once I get this resolved.

Bradley

Thorn Garden Observatory
http://astronomy.thorngarden.net

----- Original Message ----- 
From: "Gene Horr" <genehorr@houston.rr.com>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Wednesday, July 27, 2005 6:30 PM
Subject: RE: [APML] Drift alignment problem - wedge mounted scope


> Could it be mirror flop?
>
> On MAPUG it has moved.  If you go to the Topical Archives page they have
> a link to subscribe on the new server.
>
> Gene Horr

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