Date: Wed, 4 Nov 1998 05:40:40 -0700 (MST)
From: Russet McMillan
Subject: 3.5m Night Log 981103
			     Tuesday, November 3rd 1998
			     APACHE   POINT  OBSERVATORY
				 3.5-meter Observing Log
                                 ACTUAL
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ASTRONOMER      OBSERVER(S)      INSTRUMENT     DATE     START  FINISH
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Turner          Hastings         SPIcam        11/03     18:34  19:09
Harrison        Harrison         GRIM II       11/03-04  19:39  00:10
Chanover        Chanover         GRIM II       11/04     00:10  05:00
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 INST        SCHEDULED     WEATH     EQUIP      OBS      DAY   NOTUSED
I/RS/DN    START  FINISH   D    B    D    B    D    B    USE   D    B
----------------------------------------------------------------------
PU01/S     18:34  19:24    0    0    0    0    0   0.8    0    0    0
NM05/R     19:24  00:10    0    0    0    0    0   4.8    0    0    0
NM12/R     00:10  05:00    0    0    0   0.8   0   4.0    0    0    0
                     -------- ACTIVITY LOG --------
1st half observing specialist: Camron Hastings
	The dome opened to begin cooling at 17:00 with low humidity
and clear skies! SPicam was mounted and bias frames revealed a strange
read noise not seen before. It turns out that some of the oddness was
being created by ximtool, but after that was isolated there was still
a slightly sawtooth?/sinusoidal? noise beeing seen across the chip of
about 2-3 ADU. Other than that, SPIcam performed wonderfully and we
enjoyed our first night of good seeing in quite a while. I obtained
some very nice lens object images for PU01 tonight with seeing of
0.77" in a 60 second frame!
	To address GRIM's problems from last night I began running 2
second dark exposures with GRIM at 16:20 MST in hopes of warming the
electronics enough to avoid last nights problems with NM05. It seems
to be fine now and running smoothly after about 20 minutes of
problemed operation in the very beginning.
	Jon Davis and Dave Woods finished a nitrogen purge of the PMSS
today in hopes of removing any condensation that may have been causing
the oscillation problems. It seems to have worked as the system was
tested at 45 degrees today at about 3pm without any oscillations
apparent. The image quality this evening seems to support the idea
that the fix is holding.
2nd half observing specialist: Russet McMillan
At around 01:10 Nancy Chanover reported that some of her 20-sec images
of Saturn were "smeared."  I was unable to tell for sure whether this
was a tracking problem or a PMSS oscillation, but I suspect the
latter.  The TCC showed no interruption in the tracking.  I checked
the PMSS pressure, which was normal.  The problem went away after a
couple of exposures, so I didn't attempt to change anything.  But it
appears the nitrogen purge may not have fixed everything.
Again at 02:05, images of Saturn appeared "fuzzy," then around 02:50
stellar images were visibly smeared in what appeared to be discrete
jumps.  More Saturn trouble again at 03:03, smearing in a different
direction than the stellar images although the telescope and rotator
position had not changed much.  At 04:23, Chanover reported that she
had seen bad images for over 15 minutes, and these continued until the
beginning of astronomical twilight.  They may or may not have been
exacerbated by the low altitude ( 1 micron per 0.1 cu.ft.
                            TELESCOPE STATUS
Primary, secondary, and tertiary mirrors in place and collimated.
Primary support system operational. Mirror ventilation system in
place.  Telescope drives operational. Current Remark version: 2.42a
Current guide software version: GIm Ctrl v3.0b 15.out
- Camron Hastings, Russet McMillan