Re: [APML] ST-4 question-UPDATE WITH NO RESOLUTION

["William R. Mattil" <wrmattil@ix.netcom.com>]

KGKIRKLEY@aol.com wrote:

>
> In a message dated 9/9/04 3:07:29 PM, alanv12952@yahoo.com writes:
>
>
>> I have sent a detailed e-mail to SBIG and await a reply. They have
>> always been VERY responsive. My only fear; lost imaging time due to
>> travel back and forth to SBIG. I guess I could always try the 201 on
>> the G-11/Gemini. Level3 is supposed to be compatable with the Meade
>> guiders.
>>
>> Thanks all,
>> Alan
>
>
>
> Alan:
> Now that I know what mount you are using, my guess is that the Gemini 
> is the problem.
> The Gemini Go To system (especially the most recent) has problems with 
> guiders that use relays, such as the ST-4 and STV.
> The problems manifest themselves by calibration problems and not 
> making corrections in one or more axes.
> I am not an expert on this problem, but Bill Mattil is, as he's been 
> fighting this problem since spring.
> He finally contacted Gemini and they admitted a possible problem and 
> suggested a fix of soldering a jumper somewhere on the circuit board. 
> This has much improved the situation.
> Bill is on this list and has posted this info before and will no 
> doubt, respond.
>

Hi Kent, Alan,

I think Frank hit the nail on the head in a previous message. Focus. 
Assuming that the chip is *not* frosted over and that the glass is 
clear/clean and that the power supply is up to snuff and the voltage 
regulator on the ST-4 is functional (A web search on this problem is 
interesting) the most obvious culprit is focus. The fact that Alan is 
using a piece of equipment, A Tarus Tracker, lends more credibility to 
that fact as it is something else that can slip or change. Personally 
Alan if it were me ? I would bypass all the extra crap and put the ST-4 
directly into the focuser and refocus. Trivial - takes about 5 minutes 
and would prove the point. Obligatory note: This is not to demean the TT 
in any way. Its just something else that can go wrong :). I have had the 
same thing happen with the Flipmate and it can surprise you when it happens.

PS Kent I also have Rockett's ST-7 tracking the G-11 now with no relay 
boxes or other widgets. The set-up is even more bizzare (read as out of 
my comfort zone) than I expected. But it does calibrate and track. 
Trouble is there just aren't very many guidestars to fit on the 
chip......Particularly with the 253mm f/15 Cassegrain :( Did you buy 
that R/C yet ? :)

Regards

Bill

-- 

William R. Mattil  :  http://www.celestial-images.com


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