>Date: Tue, 21 Jul 1998 11:29:04 -0500
>Subject: [M]: RE: OT: Polar drift aligment


>Keep aligning. Since you cannot orient the scope such that it sees a
>star exactly on the east (or west horizon), you have to position the
>scope such that it's an hour or two in right ascension off of the
>horizon. Because of this, when you drift align for the latitude
>setting, you've also introduced an element of drift contribution from
>the RA axis also. This is generally not a problem in terms of
>performing the drift alignment of the azimuth adjustment since it's
>usually possible to find a star on or very near the meridian. So, do
>your first set of latitude and azimuth drift tests and adjustments, and
>if you see a residual drift as you've noted below, perform a second set
>and recheck. Do this until the overall drift is within acceptable
>limits. As for the east-west leveling problem, theoretically this
>shouldn't be a problem in terms of using the polar alignment routines
>with the LX200 scope (although I don't know if the version 2.4 ROMs even
>have this routine) but all that a leveling problem will do is just make
>the drift routine take more time since you have to remove that error
>during the alignment process. The end result will still be the same.


>Mike

Mike,
I see your point on residual drift from the fact that one cannot drift align

on a star directly at the east (or west) horizon. I'll keep aligning!
I'm not using the polar alignment procedure of scope. With a permanent pier,

it is just a matter of attaching the scope and sync. on a well known object.

>Date: Tue, 21 Jul 1998 07:36:53 -0700
>Subject: Re: [M]: OT: Polar drift aligment
>
> Dec drift alignment will remove all North to South movement but the
>East/West is for the RA and the PEC will remove most of this
>misalignment. Leveling will help in a CCD guider by eliminating
>corrections in x and y directions at the same time. Drift alignment only
>removes Dec drift..............................ric
>

Ric,
It took me a while to understand your point, but of couse you are right. All
misalignment of the pier (both south-north and east-west) will result in a
north-south drift
in the EP.

>Date: Tue, 21 Jul 1998 14:10:13 -0500 (CDT)
>Subject: Re: [M]: OT: Polar drift aligment
>
>It takes some experimentation to get to know that "X" amount of drift over
a
>30 second time means you are about "X" degrees too far in the "X"
direction. Once you have
>done it a few times, it becomes much easier.

Gary,
I agree, what really helped me was to obseve the drift at fixed intervals
(finally a use for the
build-in timer function of the LX200). I used 5 minut intervals, and quickly
got an idea of how
much adjustment was needed to reduce the drift by a certain amount.

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