Hi, I'd be interested to have your opinion on something as we have virtually the same equipment.
My eqpt. Celestron CPC925 on ALT/AZ mount, Orion Starshoot Autoguider, Orion Mini Guidescope, PHD Software, Mac OSX 10.8.x
First thing: The autoguider gives me a nice clean, focussed image and PHD can detect and lock onto (green box) a star with ease in loop mode, even with me moving the scope with the hand controller at centering speeds.
Second: PHD is talking to the mount. The manual controls in PHD move the scope in the correct sense.
Third: I have turned OFF backlash compensation.
After careful observation of what PHD is doing I found that whenever a pulse is sent to the scope, tracking ceases for the next 25 seconds on that axis before resuming. So, if a short pulse is sent to the RA axis, the star would then drift at sidereal rate (due to there being no tracking in RA anymore) PHD would attempt to re-aquire the star, but even with the autoguide speed set at maximum (sidereal rate) there was no way for PHD to catch up even with maximum pulse length set to say, 3000ms. Consequently an error flags up.
The same would happen in DEC.
In summary; any pulse sent to the mount rom PHD via the SSAG would cause the mount to cease tracking, in that axis, for the next 20-25 seconds, allowing the star to drift away.
The question is, why is it doing this?
Apart from that, everything works perfectly.
I don't know if this is an SSAG problem or a PHD software problem.
Any ideas anyone?