[evlatests] antenna 21

[Ken Sowinski]

Today's tests were much fragmented by the correlator meeting.

Antenna 21 has strange problems that I don't think I can
explain entirely by pointing, delays, or winds.  Staring
at it for a few tens of minutes there are many phenomena.
The amplitude varied more or less smoothly by a factor two
on a baseline with a nearby antennas over tems of minutes.
Sometimes AA was higher than CC sometimes lower.  There
were ocassional jumps in phase for one recored always in
both IFs at the same time, ocassional jumps in amplitude,
and sometimes both amplitude and phase at the same time.
There is data starting about 2130 IAT L, X and K bands.
A long track at K band begain around 2200 and lasted about
an hour.  It might be instructive to look at that in
more detail to see if any patterns emerge.