[evlatests] X-Band PDif troubles

[Rick Perley]

     A 3.5 hour antenna gain-elevation test ran last week -- 
unfortunately, the script aborted too soon for useful gain functions to 
be determined.  But the data are of quite good quality, so some other 
checks can be run. 

    At X-band, I find:

    a) There is no useable switched power (PDif) on ea02 and ea27 on any 
IF.  All we see is zero-mean noise. 
    b) There is no useable switched power on ea12D.  The other IFs look 
good.
    c) A number of the IFs show apparent gain changes which are likely 
due to bad switches.  (X-band follows Q-band in these tests).  The most 
notable unstable antennas are:

    ea08A
    ea18A and C
    ea20A
    ea23B and D
    ea25A and C
    ea26A