CEM70 Guiding Troubles- Large RA peaks causing Elongated and Bad Calibrations

[Vince Tambellini]

Hello,

Here is the link to my logs: 

https://openphdguiding.org/logs/dl/PHD2_logs_yd2v.zip

Basically, I have been having troubles for the past few weeks on my CEM70.

I am running:

840mm scope at f7

ASI2600mm camera

OAG with 220mm guide camera

CEM70

Summary:

I am getting decent overall guiding, around 0.4RMS, but the peaks in mostly RA and now DEC are elongating my stars, in especially RA. They are very frequent. I have worked out some of the error, so now the elongation is less than it was, doing things like changing the guide settings. However, I can still see some smearing of stars at 60 second exposures, and at 5 mins they do not look great. There has been a weird period wave on + and - error of RA, and now DEC has really huge adjustments frequently.

Current status:

I do not have an issue with Polar alignment. The dec backlash might be an issue or an artifact of that period stuff.
A lot of the parameters are pretty well fined tune now. Ignoring that first period could be a few minor things including chasing seeing or the dec backlash which may or may not be real. Need some help on the RA axis and setting changes probably are not going to do much for it (at least not with PPEC) at this point. Hard to say though and unsure. 

On the logs:

One of the guide logs really started at around 1 or 2am after tuning settings. The one from tonight is much shorter. Another issue is whenever I use 2 seconds things get a lot worse, so been using 1 seconds I suppose. m

On Calibrations:

Also, calibrations tend to be poor- it also seems like phd2 when trying to point to 0/5 for best calibration, that's actually the incorrect location- so I've been manually slewing to 0/5 then calibrating. Also, the calibrations are almost never orthogonal. 

Not sure what else to mention- please let me know if you need additional information. 

Thank you,

Vince T