[evlatests] Tests April 13

[Barry Clark]

1.  Did pointing at C band.  Vivek analysed antenna 13.  Main error
term was az rotation of 2.66'.  Put it in the database, guessing which
sign.  Handed subarray to Rick, who promptly broke everything.

2.  Tried 4 band; report already from Walter.  I was watching baseline
4-14 as I went, with slightly different descriptions from what Walter
said.  a.) raw fringe amplitudes were about a factor of 10 lower on 4-14 
than on 4-5.  b.) fringes did not go away when I stopped the executor.  
They quickly dropped a factor of 5 as I moved the antenna, and another 
factor of two by the end, when we were looking at the source in the backlobe.
But still there.

3.  Running VLA antennas.  Still serious timing problems.  Had to search
for the right offset to sync the waveguide cycles.  Synced up at a 
synctime of xx:xx:x9.5955.  Later on they came unglued again and 
I had to change the synctime to xx:xx:x9.6996.  Perhaps our NTP was
wandering around, maybe by enough to cause Rick's problems.  (Last
week I started out syncing at xx:xx:x9.6996 and had to switch to 
xx:xx:x9.7517 later in the day.)  However, progress:  setup for four
bands seems to work OK (after I corrected the sign of subreflector rotation 
in the database for antenna 6 at X band):  C, U, L, and X.  K band has the
wrong first LO setup, and there were no fringes at Q band, for no obvious
reason.  Didn't try P band.