[evlatests] Antennas with flaky switches at X-band

[Rick Perley]

    The flux densities run required about 2000 band changes over the 30 
hours -- a good test for the reliability of the band switches. 

    The X-band system seems particularly susceptible to the PDif changes 
which we associated with bad switches.  (In short, power changes of less 
than 1 dB, and time variability within a single scan).  The following 
antennas were especially ratty in their PDif values.  Note that the BD 
side was tuned to 11.0 GHz, so only the new receivers gave data. 

    1 A, C
    2 A, C
    4 A, C
    8 A
    9 A
    13 A, C
    14 A, C
    16 A
    19 C  -- this one is especially bad!
    20 A
    24 A and C
    26 A
    14 D
    16 D
    18 B and D -- these are really, really bad (showing major power 
changes which may be unrelated to the switches)
    24 D
    25 B
    26 B and D

    All the others are quite good.