Date: Mon, 22 Mar 1999 05:43:48 -0700
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m obslog 990321 ( MJD 51259 )
                           SUNDAY MARCH 21, 1999
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
   It was another good night tonight.  Skies were clear all night.  Seeing
was between 1.0 and 1.5 arcseconds the entire night.  A northern strip
science run  ( 756 ) was started at around 20:15 and it went until about
04:15 when AD3 died at frame 817.  Even with the premature demise of the
DA, I think that may be the longest continuous science run to date.
   The enclosure was rolled off at around 18:20 after being closed all day.
The exhaust fan was turned on at about 16:50.  Again, images tonight looked
good from the start.  The focus loop also performed well tonight, running
for more than 8 hours continuously with no trouble.
   There was one odd occurance with the altitude upon setup tonight.  When
starting to raise the telescope out of stow once the building was off (
about .8 on the clinometer ), the telescope itself began to oscillate in
altitude, not terribly, but enough that it got the windscreen to bounce
back and forth as well.  The amplitude may have been a few tenths of a
degree, and the period about two Hertz.  Issuing an "s" in the menu, then
reissuing the move, cleared up the oscillation.  In case it means
something, the velocity for the move to position was 70000 cts/sec.
   As for the death of AD3, its cause was not readily apparent.  It was
decided to leave things in a crashed state in case something could be
learned by others checking on it during the day.  This is the same node
that hung last night as well.
                                Mirror Numbers
  Primary numbers:
   setmir:  0 -25.8  17.2  939  1409
   galil:   6300 -3850 150 9700 24750 24100
   linear guages:  1:+01.9270
                   2:+00.5600
                   3:+00.5560
                   4:+00.3565
                   5:+01.9290
                   6:+00.4300
   Secondary numbers:
   setmir:  1460*  -255   0   0 133
    galil:  1696000,  1776000,  2044750, -9650, -16650
       *The piston was taken over by the focus loop and did not remain here.
   The enlosure was closed at about 05:00.
                                   Dan