Hi!
I've recently upgraded my C8 to a C11, and accordingly, things
started becoming problematic after that....? particularly my
guiding. I have an older G11, with OPW on the RA axis. I normally
have 0.6 - 0.8" RMS before, now I struggled a lot to come below
1". Most particularly, there has turned up some new "bumps" in the
RA and in general RA RMS is around 2x DEC RMS, which is not good
for my stars (elongated).
So I have been doing polar alingment, adjusting the RA worm and
all. And finally got it all to play nicely, I get a rather smooth
curve when doing unguided gudiing assistant in PHD2 or acquiring
data in PEMPro. The PE is a bit to big (some +/- 7") but that is
not much cause for worries when it is smooth. Frequancy analysis
shows almost nothing execpt for the worm ger at 239 secs. Nice!
So I capture a PEC curve and program my mount. And I see an RMS
of about 0.5". I am a happy amateur... for a few minutes. Then
there are some "bumps" coming on the curve. Now what is this? So,
here is my question to you - what might it be that causes this?
Attached is a PHD2 log from last night. There are a lot of
sessions because I do variable stars. But session 15 is the one I
am interested in now - the long one. There are a number of big
bumps, but since most are in RA and DEC at the same time, I assume
that is external things, like a wind gust or a bird landing on the
scope.
But when I choose a section betwen those bumps
and do a frequency analysis, I get a contribution from something
that is around 60 secs. This is the one I worry about now. See the
attached screenshot from PHD2logviewer frequency analysis window.
Anyone got any idea what might cause this frequency? I know of the
76 secs and the 31.9 secs, but this one....?
Any help much appreciated.
Magnus
