Date: Mon, 10 May 1999 05:47:44 -0600 (MDT)
From: Russet McMillan
Subject: 3.5m Night Log 990509
                            SUNDAY MAY 9, 1999
                         APACHE POINT OBSERVATORY
                              OBSERVING  LOG
                                                          ACTUAL
ASTRONOMER      OBSERVER(S)        INSTRUMENT   DATE   START FINISH
Tripp		  Tripp		    Echelle    5/9-10  21:24 23:10
Davidsen      Tsvetanov, Zheng        DIS       5/10   01:10 03:20
 INST        SCHEDULED     WEATH     EQUIP      OBS    DAY   NOTUSED
I/RS/DN    START FINISH   D    B    D    B    D    B   USE   D    B
PU05/S     21:24 01:10   1.0   -   1.0   -   1.8   -    0    0    -
JH05/R     01:10 04:35    0   1.3   0    0   1.9  0.2   0    0    -
(note: times listed include instrument change time)
                              ACTIVITY LOG
(* means a trouble report has been issued or appended to)
1st half observing specialist: K. Gloria
The telescope was opened at 19:30, after the wind died down a bit.
Todd Tripp was on site to observe with the echelle.  He got one set of
observations done before we had to close at 23:10, again due to wind.
The pointing was good.  Stars were landing within 5 arcsec of the
slit.  The observations went very smoothly.
2nd half observing specialist: R. McMillan
The wind dropped at 00:10, and we opened to find a curious problem.
As soon as the last stop button was released, a distinct hum came over
the intercom, rather high-pitched.  It turned out to be coming from
the azimuth drive motors, which were vibrating so strongly the sound
could be heard well into the walkway to the ops building, and the
entire base of the telescope was vibrating to the touch.  When a stop
button was pushed, the hum did not stop.  Karen turned off the raw
power to the azimuth control box, and at that point the hum did stop.
When the power was turned back on, the hum didn't come back.
Jon Davis came in and spent a little while trying to find the cause of
the hum.  He did find a malfunctioning fan, which he fixed, but it
seems unlikely that a fan that *wasn't* turning would cause a
vibration.  We resumed observing without ever tracking down exactly
what had happened.
Observations with DIS went smoothly, although the seeing was poor and
some clouds had begun to appear.  The telescope was closed again at
03:20 due to rising dust, and never re-opened.
                            OBSERVER COMMENTS
                                FOCUS LOG
                               MAY 9 1999
						 Wind
Time   Inst        Focus     Az  El   #Temp    Dir  MPH  filt  FWHM "
21:15 echelle  -800(5735)           11.6/12.0  255  20   ND 1   1.4
22:00 echelle  -800(5700)           10.9/11.3  248  17   clear  1.2
23:00 echelle  -775(5705)           10.3/10.7  256  23   ND 2   1.2
01:15 slitcam   120(6658)   220  49  8.3/8.7   270  28    --    1.8
#First temp is air, second temp is telescope.
                                 WEATHER
                               MAY 9 1999
                               Wind
     Time   Temp F Dewp F  MPH  Direction    Dust      Sky      Precip.
     16:01    63    18     26   264  (W)     1962     clear      none
     17:01    62    17     26   260  (W)     2201     clear      none
     18:01    59    16     27   264  (W)     2155     clear      none
     19:01    56    12     29   259  (W)     2317     clear      none
     20:01    53     9     28   251  (WSW)   2316     clear      none
     21:01    52     9     24   267  (W)     2737     clear      none
     22:01    52     9     23   261  (W)     2638     clear      none
     23:01    51    11     25   264  (W)     2443     clear      none
     00:01    49     8     25   267  (W)     2328     clear      none
     01:01    48     9     20   257  (WSW)   2546     clear      none
     02:01    45     8     14   266  (W)     2281    mstly clr   none
     03:01    45     4     22   283  (WNW)   3318    mstly clr   none
     04:01    44     6     18   271  (W)     3760    mstly clr   none
     05:01    42     6     16   267  (W)     4003    mstly clr   none
note: the wind was coming from the azimuth listed.  The convention
used is north=0 degrees, east=90 degrees.  The dust count is particles
> 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: 2.52
Current guide software version: GIm Ctrlv3.0b17.
- Karen Gloria, Russet McMillan