I had written a whole nice note with photos and arrows and a paragraph on the back of each one explaining what each one was but realized that I had failed to enter the image scale as best as I could figure it out. I'm still not sure that I did that right, but here goes:
First of all, I don't recall seeing you post this over on the Bisque site. If you haven't then you should as there are a lot more Paramount owners over there and that's where the Bisque staff review problems and respond to questions.
Second of all, I know nothing about PhD, so I'll confine my comments to the mount's tracking log. The tracking data looks fairly reasonable, I don't see any strange periodic jumps nor do I see any glaring correlation between the axes. For example, if you look at your tracking log with the autoguider graph utility:
All I see if the not-uncommon gradual drift in RA & declination, although there's a bit of a more rapid fall off in dec where it crosses the center line. The RA shows a fairly regular sinusoidal kind of curve. If this log was taken at the same 6.45 AS/pixel image scale that the PhD log indicates, that's kind of more drift that I'd expect depending on how you aligned the mount.
When you load it into the PEC function under the Bisque TCS utility, the cleaned & normalized RA curve looks pretty nice. Again, I don't see any strange periodic jumps:
The double hump is a little odd, but it's smooth. Now, what is the image scale of this thing? Like I said, your PhD log indicated that you had a pretty low-resolution image scale of 6.45 AS/pixel at only 120mm focal length. This is the value that I used in the graph above. Is that accurate and is it the same camera that you used to record the mount tracking log?
So, does that jump that you're seeing show up in the PhD log (I don't have PhD so I can't look), because I'm not seeing anything obvious in the mount's tracking log. How do the actual sub-frames that you're acquiring look? Also, if you are guiding with a finder/guider, how is it attached? Is everything tight? What is the rest of the rig? Do you have any moving mirrors or other floppiness? What's your seeing like? The guider settings aren't really aggressive are they? Have you programmed a PEC curve? Was the curve activated when you shot that tracking log?
Sorry, no brilliant ideas. Just questions. Maybe post all of this over on the Bisque site.
Edited by Ken Sturrock, 25 January 2020 - 07:39 PM.
had to rework the graphs and further pontificate