VLA Test/Observation Coordination Meeting
                           B.G. Clark
                       February 20, 2003


1.  Polarization at K band

Dwarakanath has examined the frequency dependence of the D terms
at K band, over the range covered by the current receivers, roughly
20 to 24 GHz.  First, it is encouraging that the solved polarization
for 3C 286 is nearly constant across the band, with one point 
deviating by about 0.2%.  The D terms are also rather constant
across the band.  The six old receivers have systematically 
different D terms, as might be expected.  There is a weak suggestion
that they might also be more variable; but this based on a solution
on 3C 286 (taken 16h after one on 3C 84) which is susceptible to
other influences.

2.  Iridium filters

M. Claussen reports that he ran a quick test on the Iridium filters
which have now all been installed.  These are 3 MHz wide filters
centered at 1611.9 MHz (nominally, anyway), to permit observations
of 1612 OH in the presence of the Iridium satellite system, and in
particular, to eliminate the effect on calibration on the beat 
between the Iridium TDM heartbeat and the VLA 19.2 Hz heartbeat.
The bottom line is that the 1612 line system appears usable.  There
were, however, a good number of one-off anomalies.  There were 
perhaps half a dozen IFs for which switching in the filters did not
work at all, and a moderate number of IFs with more subtle problems,
which MC was inclined to attribute to the filters being mistuned.

3.  Odds and ends

K. Sowinski reports that antenna 6 now has a new K band receiver,
but mounted in the location of the old K band receiver.  There were
problems in fitting it into the existing "dog house", and it apparently
ended up a long way out of focus.  The K band receiver for antenna
22 will also be installed in the "dog house"; after that, the entirely 
new eVLA focus arrangement will be used.

R. Perley says there was an observing run for calibrator ratios and
gain curve determination on February 6.  This will not get reduced 
until the EVLA phase II proposal is completed.

C. Carilli reports that Antenna 5 will have its surface set according
to 7mm measurements taken in October.  He plans another holography
run in April, when most of this years build of 7mm receivers are installed.

C. Chandler reports that the two water vapor radiometers have temporarily
been removed from the array (antennas 26 and 28) because they were generating 
RFI at 327 MHz.  A fix is being worked on.