Date: Wed, 26 May 1999 06:42:57 -0600 (MDT)
From: hayes@apo.nmsu.edu
Subject: 2.5 m obslog for 990525 (MJD 51324)
			Monday May 24, 1999
                   Apache Point Observatory SDSS 2.5m
                           Observing Log
Observing Team:
		Jeffrey Hayes (APO)
		Ellyne Kinney (APO)
                Jim Gunn (PU)
		Adrien Pope (CMU)
		Francisco Castander (UC)
		Russell Owen (UW) -- remote
Weather:  Clear.  Winds: ~20 mph steady
and gusts up to 30 mph.   Low dust and humidity.
On tap tonight, a third try for: using the pointing model
from 20 May and conduct guiding tests for the spectrographs.
The CW were still set of 340 for the cartridge + corrector combination.
The opening fiducial settings were:
AZ    120:22:15:755
ALT   14:53:10:134
ROT   00:59:43:130
We note that after releasing a stop button, the resetting the amps, and then
releasing the ALT brack, all via the MCP, the ALT axis drifted down by a
degree or so.  This was a bit puzzling as the telescope was pretty well
balanced.
We successfully got stars down the fibers and guided in spectroscopic
for the first time on the same plate as was to be used last night (i.e. the
fast field.  There were some initial problems with the getting the
plate instrument block, but these were corrected so that by 1:45 am MDT,
we changed to plate 135 on cartridge 1.
We successfully changed out to the first science spectroscopic cartridge
at 2:00 am MDT, and we back on the air by 2:30 am MDT (must be a record!).
There was not the success in guiding, as the moon was fairly close and
the field was quite a bit over to the West.
We started to close up at 4:30, but as we were sending the telescope to
slow position using the TCC, the telescope started to move in AZ in the
wrong direction (i.e. instead of unwrapping, it seemed to want to go in
a more direct route to stow).  We then reverted to the MCP, but we only suceeded
in getting a few shudderings in the correct direction before the motion
stopped.  We went in the hole to see that the AZ amps for the telescope
showed "bidirectional inhibit" lights on.  We reset the amps, and tried
again -- same result -- a few shudders in the correct direction and then
a halt.  We then tried to move the telescope in AZ with the manual
paddle, and could not get any motion.  We noticed that all the AZ
interlocks in the hole were out.  We then called French at 4:50 am MDT
as we were at a loss.  It appears that the AZ fiducial reader was not
firing, so the MCP and the TCC lost track of where it was (i.e. the MCP
currently thinks that stow (120:45) is at -239 and a bit.  It then appears
that the MCP thought it was at asoft limit.  French will send around
a complete report later today.
Note:  The large 180L LN2 dewars cannot be left by the outside manipulator
arm.  At least where it was parked this night, Hayes did trip and hurt
himself (minor it is true).  We have to find both a convenient and safe
place to put these.
We finally closed at 6:35 am MDT.
Jeffrey and Ellyne