Sitech tracking drift

[Horwig]

Now I'm getting to fine tune this self built Sitech controlled mount of mine, I've noticed that it's not tracking at true siderial rate. Ticks per revolution in RA have been checked and double checked, but it's tracking slow by about 0.3%. I've started a conversation on the Sitech yahoo group, but has anybody here seen anything similar?

 

Guiding corrects for it, but it would be nice to get it right in the first place

 

**EDIT**  Sorry, was going to post in MOUNTS, mods, if you think it would be better there, would you move it, thanks.

 

Huw

[tony210]

Hi - I experimented with RA ticks per revolution with my Mesu as even when polar alignment was perfect it did not track at a  completely reasonable sidereal rate - after finding the fine tuning spot for RA ticks per revolution guiding was much better and RA corrections much less with a flatter PHD graph-you can measure RA drift and then work out fair corrections- not sure if this is useful but certainly had to work on this a little and had good results- Tony

[Zakalwe]

Yeah, I had the same issue on a Mesu.

Run PHD's Guiding Assistant and it will tell you the actual tracking error. From there it's a fairly simple calculation to work out how much to alter the Tick setting in the Sitech configuration program (Servoconfig). See this useful post:

 

[Horwig]

Now that is interesting. I've played with the ticks setting but not yet found the sweet spot, I hoped that there was something I'd done wrong as opposed to having to tweek the mount, more work needed.

 

Huw

[Horwig]

Patchy cloud here tonight, so can't get any sensible results to measure properly, but it looks like I'm running slow by about 3 seconds of arc per minute, so to correct I need to REDUCE my Ticks count do I?

 

Huw

[tony210]

Yes -reducing ticks per revolution should speed up the mount - Tony