MDM Trouble Report for 2001 Mar 23

Telescope: 2.4m
Observer(s): Bill Fenton (Dartmouth)
Instrument: modspec/echelle

Problem(s) Encountered:
While I was focusing the modspec for the first night of my run I 
found that the minimum FWHM was about 3 pixels rather than the 
expected 1.5 or so indicated by past set-ups.  I believe that 
the dial indicator for the slit jaws may be
in error (even more than previously believed.)  I was told that
a reading of 00  50 indicated a one arcsecond slit width.  The 
minimum FWHM I achieved at that setting is not consistent with 
previous set-ups.  I finally acheived a reasonable FWHM (1.8) by
simply narrowing the slit width.  The dial indicator now reads 
99 65 i.e. below zero!  I hardly lost any photons at all from 
00 50 to 99 65.  I'm not sure what is going on but I seem to be getting
good results now.


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Submitted on 2001 Mar 27 [7:25:21]