G'day Paul, I have a NEQ6 which had graph similar to yours but was perhaps a little more spiky, although I could still image at 10 mins subs with round stars,...... go figure
. I eventually got my rms down to .6 (on a good night) by the following.
1. I hypertuned the mount, (didnt replace any bearing).
2. fitted a Rowan belt kit
3. Run PEC in EQmod
4. Run Predictive pec in PHD2
My mount works well now, rms will still move over 1 on a poor seeing night which is to be expected.
I used to look at some of the almost perfect graphs on other forums and wondered how they do it on cheaper unmodified mounts in light polluted cities, something did not ring true to me, the reason I mention this is because I went down this road, spent a lot of unecessary time trying to get a near perfect graph, which I stil am unable to achieve, my graph still spikes a bit but I've got tight round stars, thats all that counts in the final washup.
These links may help,
https://groups.google.com/forum/?fro...en-phd-guiding
http://www.astro-baby.com/EQ6%20rebu...own%20Home.htm
If I can help with any of the above let know
Hope this helps Russ