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Old 03-09-2014, 05:39 PM
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Peter Ward
Galaxy hitchhiking guide

Peter Ward is offline
 
Join Date: Dec 2007
Location: The Shire
Posts: 8,112
Quote:
Originally Posted by clive milne View Post
That is true Peter,
It is also true that a direct drive with an autoguider (or autoguider+AO) is going to have better performance than a geared drive on the same mount.

(assuming it is engineered and tuned correctly)
Unfortunately I've not had an opportunity to test that thesis. What I have found true, using 5-7hz closed loop sampling, is the star sizes that my system generates are only effected by seeing.

I've certainly pondered: would better results be obtained with a drive system that tracks well below the seeing noise?

Running some back-of-the envelope numbers, I suspect my PME is already there, as being in a dome, there is no wind buffeting. Hence, over a 1 second interval, the drive would only have 2arc sec/720 seconds or a .003 arc sec error.
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