Re: APPC RA rate

Howard Hedlund

Hi Craig,


You will most likely find that your rate will not work all over the sky.  APCC Pro’s pointing and tracking correction will most likely be a better solution.  Kudos, however, for nailing the polar alignment.  Many people only focus on Declination drift when polar aligning, but tweaking the altitude to minimize RA drift is equally important.


As for a permanent custom tracking setting, try setting BOTH the AP V2 driver and APCC to the custom rate.  ASCOM rules (as I understand things) call for restoring tracking after any movement.  If the driver has not been set to the same custom rate, then any slew or button move from a client program will result in a call to set the tracking to sidereal.  I did a quick experiment here in the office, and this worked for me.


Mag. 7 Skies!


Howard Hedlund

Astro-Physics, Inc.

Phone: 815-282-1513

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From: ap-gto@... [mailto:ap-gto@...]
Sent: Tuesday, August 22, 2017 6:00 PM
To: ap-gto@...
Subject: [ap-gto] APPC RA rate



Mount: AP1600GTO w/encoders
Scope: GSO 16" RC (fl 3250)

I am finally able to take 600 second images repeatedly with no guiding.  To do this I had to do two things: first, get the polar alignment very accurate, and second, set custom tracking rate of -0.00100 for RA.

The problem I now have is every time the telescope is moved, the tracking rate is returned to Sidereal and if I forget to change it back to Custom then I get elongated stars.

Is there a way to permanently set the tracking rate in RA to this custom value and not have to change to custom?



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