Re: [APML] A question for you ST-4 experts

[Chuck Vaughn <aa6g@aa6g.org>]

Alan,

I don't know anything about the 201XT (except for all the bad  
reports) but I've used the ST-4 for 15 years and I never have it run  
25 during calibration. I usually run 10 or a little more. If the  
object is far north the RA may only be 6 or 7. I believe 5 is the  
minimum that the ST-4 will accept without a calibration error. Mine  
guides just fine. I'd be extremely doubtful that a larger calibration  
travel would make any difference in the guiding accuracy. The ST-4 is  
not the 201XT.

Chuck

---------------------------------

> Hey all,
>
> I've got an autoguider calibration question I want to lay on you guys.
>
> First, some history. I've used the Meade 201XT (Rich Michaels; where
> are you now?) on my LXs for quite awhile. There has been past
> discussion that increasing the calibration numbers will result in
> better, smoother guiding. I tried this, and it worked on the 201 and
> LX200 mount. Somewhere in the MAPUG archives is an article I submitted
> regarding this issue. Ralph Pass is the one who originally suggested
> doing this, it also worked for him.
>
> I wonder if this is worth pursuing on the ST-4 and G-11. Has anyone
> checked this out and were there any results worth mentioning? I
> currently start calibration with the star roughly centered and use  
> '20'
> for calibration numbers at 820mm focal length. That moves the star to
> about '75' and '15'. If I started with the star at '15' and '85', I
> could use '40' as the calibration entry and keep the star on the chip,
> and have twice the movement during calibration. Hopefully, this would
> improve guiding performance.
>
> OK, any insights at all out there?
>
> Thanks,
> Alan
>
> SCT Astrophotography: http://www.pbase.com/avoetsch/astrophotography
> FS-102 G-11/Gemini: http://www.pbase.com/avoetsch12952/tak_fs102
> & http://www.pbase.com/avoetsch12952/fs102
> & http://www.pbase.com/avoetsch12952/takpf
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