Poor RA Guiding

[Tim Stevenson]

Bruce and Brian ... I just keep coming back with more issues.  My setup is the EQ6R Pro with an AT8RC telescope and an OAG/ASI220 mini guide system.  My last issue is now gone when I disabled Dec backlash and in fact the Dec guiding is very good IMO.  But, the RA is twice that of Dec.   I'm using Predictive PEC with the standard settings with the only exception being the period is set to 480 period length.  The RA motion seems very erratic, i.e. back and forth, while the Dec is much more stable.  I'm wondering if it's stiction causing the back and forth.  I have it in Dec as it showed up in the backlash chart on my last post.  If so, then i probably will need to work both axis worm gear adjustments.

Thank you again

Tim Stevenson

https://openphdguiding.org/logs/dl/PHD2_logs_9Ek7.zip

[Tim Stevenson]

Adding a little more information... Segment 6 leading up to flip, guiding was RA 0.56" / Dec 0.48" with a Total of 0.74".  Not bad.  The frequency analysis show all peaks gone thanks to Predictive PEC algorithm.  In segment 7 after the flip, guiding was RA 0.67" / Dec 0.29" with a Total of 0.73".  This segment is still has reasonable guiding but this is were I noticed the RA 2x Dec.  Also the frequency analysis shows the 181 and 121 Hz peaks.

Before I show you some of the screenshots.  I noticed a large difference between the Dec MinMo (0.35) and RA MinMo (0.23).  Also if I were using  Hysteresis algorithm and saw this bouncing I would reduce aggressiveness.

Thought I would show you the "bouncing" around of the RA guiding as seen in Segment 6...

Segment 6 frequency analysis.

and here is Segment 7 frequency analysis.

Here is the Frequency analysis with Hysteresis algorithm (several days earlier).