MDM Trouble Report for 2007 Apr 22

Telescope: 1.3m
Observer(s): J. Bird & L. Watson (OSU)
Instrument: CCDS

Problem(s) Encountered:
The dome:
When starting up, we reset the dome azimuth encoders at the home
position.  But on our second object (~8:05pm), we noticed that 
the telescope was still not pointing out the center of the dome
opening when the the tcs monitor said that it should be (when 
either the asterisk was in the center of the graphic or when the 
dome error was smallest).  We reset the dome encoders at the 
home position again, but when we went back to our object 
position, the tcs monitor said that the dome azimuth was 217.3 
when by visual inspection inside the dome, the azimuth was 
actually 258.  We again reset the dome encoders, this time at 
our current position of 258.  Since the tcs graphic and dome 
error did not seem to be reliable, our temporary solution was
to look at the telescope's position with respect to the dome 
opening when we moved to a new object, note down the dome 
error when the telescope was best centered in the opening, 
and keep the dome error at that value for the exposure.  This 
worked well.  Example values for the dome error that best kept 
the telescope centered in the opening for various objects were
-3.2, 8.6, 10.5, and 1.6.  So these are not consistent with
one another and the asterisk was rarely near the center of the
tcs graphic when the telescope was in fact looking out the 
center of the opening.

At ~12:10am (during an exposure) we noticed that while we were 
making a very small adjustment to the dome position that the 
tcs monitor dome error jumped from ~1 to 50.6.  We kept the dome
where it was because we knew it hadn't really moved that far
and when we checked at the end of the exposure, the telescope
was still pointed out the center of the opening (so no light
was lost!).  Additionally, the tcs dome azimuth displayed was
350 when the actual azimuth was 304 (~50 off).  This jump in
the reported tcs azimuth occurred again at our next object at
~1:20am, again when me were making fine adjustments to the dome
position during an exposure.  This time the dome error jumped
from 8 to -7.1.

The electrical surge:
We also experienced a electrical surge at 3:20am.  This caused
the telescope to stop tracking for some reason.  We officially
turned off the tracking, turned the telescope power off, 
and restarted the power and tracking.  Doing so made the tracking
start working again.  Hopefully nothing else was damaged during
the outage (or surge?). 

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Submitted on 2007 Apr 23 [5:38:55]