MDM Trouble Report for 2009 Jun 13

Telescope: 2.4m
Observer(s): John Thorstensen (Dartmouth)
Instrument: modspec+echelle CCD

Problem(s) Encountered:

The shutter in the modspec started failing again, intermittently.
On some exposures it was fine, and on others there was little or
no light getting through.  I pulled the shutter assembly from the 
spectrograph, and with Don Terndrup's help I exercised the 
shutter -- it looked fine.  I put it back in, and it was OK for
a while, but then the problems started recurring, so I pulled
it again and tried an exposure without the shutter -- there was
a very large increase in throughput.  So, the shutter was 
definitely the problem.  I left the shutter out
and attempted to swap out the bad unit, but found it was 
beyond my skill set.  I might have been able to deal with the 
odd rubber-cement like stuff (if I could find it), but I don't 
have the soldering skills to rejigger the connector and 
connect it to the hole it feeds through.  So I'm just going to 
do without a shutter until it can be fixed -- it limits what I
can do, but the longer spectroscopic exposures are coming out
fine.  I cut the wires to the old shutter when I thought I still 
had a prayer of mounting the new one.  The parts are all in 
the shop area.

Also, the mirror A/C breaker did trip once, on Saturday AM when
I was asleep.  There was at least one other momentary brownout
during the day when it did not trip.  It looks as if the 
breaker trip problem has been ameliorated but not quite fully
resolved.

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Submitted on 2009 Jun 14 [5:02:48]