MDM Trouble Report for 2010 May 5

Telescope: 2.4m
Observer(s): Thorstensen and Spellmire (Dartmouth)
Instrument: modspec + echelle ccd

Problem(s) Encountered:
The echelle chip has a noise pattern in it I haven't seen -- it's
not 60 Hz pickup but a high-spatial-frequency (maybe 5 pixels) 
modulation with about 5-10 ADU peak-to-peak amplitude.  It 
resembles tweed cloth.  Bob and I saw this in the afternoon but 
it wasn't clear what to do about it (and Bob had his hands full 
with the dome encoder, which he repaired successfully after quite
an effort).  The noise is bad enough to affect the faintest 
targets.  

------------------------------

Submitted on 2010 May 6 [5:29:50]