[evlatests] Issues at X-band

[Rick Perley]

    Examination of the X-band data from last night shows a few 
interesting issues:

    Antenna 16 has cross-power low by a factor of 10 to 100.  The system 
temperature about 600K -- explaining most of the low cross-power. 

    Antenna 20 has the same characteristics as antenna 16, but not as 
extreme -- Tsys about 300K. 

    Antenna 22 is also low in cross power, with high Tsys (about 90). 

    Antenna 27 has low cross power (by 12 dB) on IFs A and C only, but a 
normal system temperature.  Attenuators mis-set? 

    Antenna 21 claims to have a system temperature of 200K, but it is 
certainly not that high, as I can see normal sky variations.  Bad Tcal 
for sure. 

    By looking at the bandpass solutions only, the following antennas 
*appear* to be wideband (meaning, there is no high-frequency roll-off):

    7, 13, 14. 

    I don't understand how 13 can have such a nice flat bandpass -- it 
is not supposed to get a new receiver until March, next year ...