[evlatests] L-band

[Rick Perley]

    All the issues reported earlier at Xband for antennas 13, 14, 16, 
18, 19, and 21 are the same at L-band. 

    Flagging issues are also similar, but with some curious differences:

    1) VLA antennas were not correctly flagged prior to their arrival on 
source. 
    2) Most EVLA antennas were flagged appropriately at the beginning.  
Two were not -- antenna 19 and 21 (which give no fringes, but are 
pointing, according to the operator).  However, there is no indication 
from Tsys data that these antennas actually did anything -- there are 
still (!) no Tsys data in the monitor data from antenna 19, and antenna 
21, although it has reasonable numbers listed, shows no variations 
expected when antennas move and change band. 
    3) For the last 10 seconds, the EVLA seems to have changed frequency 
-- or at least changed something -- as all the Tsys values change, 
amplitudes (for EVLA to EVLA antennas) change, and phases change.  There 
is no change in VLA to VLA baselines. 
    4) For the last 10 seconds, it is the VLA that got flagged, even 
though nothing happened to them.  (Exception - antenna 6 wasn't 
flagged).    The EVLA antennas were not flagged.