Good morning Brian,
Last night was clear with good seeing (here in SW Florida) and I was able to complete a guiding baseline log. ?I followed your baseline procedure with the exception that I forgot to change the G11 guide speed to 0.5 so it was at 0.8. ?I was surprised to see that the GA calculated an even higher DEC backlash than what I had seen two nights before and this is after I had tightened the DEC worm. ?Observing the baseline guiding it looked like it varied between 1.2 to 1.5 with plenty of spikes and drifting. ?I again saw that the RA is slow to move back to 0 and it takes a number of pulses to bring it back. ?The calibration is in log section 3 and the baseline testing is in log section 5.
I forgot to turn off PHD so in log section 8 you can see the results of a test sequence on M81. ?Here the only change I made was to increase the RA aggression from 0.7 to 1.1. ?The results were amazing! ?Guiding varied between 0.3 and 0.6 arc-sec for most of the time. ?That is by far the best I have seen for this mount.
A couple of questions:
As you can see, the orthogonality is not perfect. ?In the past I have seen it much worse. ?What should be done to improve it? ?I am aware of how PE can skew the results so perhaps that explains this result.
On the last two nights of testing runs the PA was ~50 arc-secs error yet when GA was run it showed larger PA errors, although still in a good range. ?Is this typical?
I am really interested to hear what you see in these results. ?Thanks for your time and effort,
Don Bishop
