[evlatests] Another instability ...

[Rick Perley]

     Finally (for now), we have 'type B' behavior.  Here there are 
changes within the switching block, seen only at high frequencies, and 
only on a few antennas, notably ea07 and ea10.

     Unlike 'type A', these variations are common between the four IFs, 
and are not seen in the switched power gains.  Hence, they act like 
optics errors -- either pointing (unlikely here since there is very 
little antenna motion within the short block), or a failure for the 
subreflector to reposition to exactly the same location as before.

     I attach four plots, showing the antenna gains for ea07 and ea10, 
for the Ku, K, Ka and Q observations.

     1) Ku-7+10.png:  There are 15 1-minute solution set , for antenna 7 
and 10.  The first 5 are alternating with K, the next 5 with Q, the last 
5 with Ka.

     2) K-7+10.png:  The 5 set on the left are with Ku, the ten on the 
right are with Q (first 5) and Ka (last 5).

     3) Ka-7+10.png: The 5 on the left are with Ku, the ten on the right 
are with K, then Q.

     4) Q-7+10.png:  The first 5 are with Ku, the middle 5 with K, the 
right 5 with Ka.

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