I tried guiding with PhD2 over the weekend and went through the calibration process once I got everything aligned etc. Calibration seemed to go smoothing without PhD having a fit about anything and I started guiding. The graph immediately took a nose dive and never recovered beyond issuing corrections which simply moved the mount between 4 and 6 pixels in whatever direction PhD fancied at that point in time. I disconnected the guiding and moved to unguided shots just to get something out of a night out.
The mount was polar aligned well and I was able to keep an object on the CCD chip for an hour before needing to nudge it back towards the centre so I am pretty sure there was nothing mechanical at play this time. I didn't have a spare ST4 cable with me and now it is cloudy and raining again. Is my assumption that the cable is likely the cause of the issue correct?
Was the scope properly balanced for the oart of the sky you were imaging? Did you calibrate before you started guiding? Did you try altering the guide period.?
Yes, balanced correctly and calibration done before I started guiding. Calibration seemed to proceed without it having an issue and then I started guiding. Tried changing the timing of the guide images from 5 seconds up to 10 seconds and let it go for a couple of minutes but the graph never cam back up, even taking it the other way had the same response.
