[evlatests] Antenna 21

[Rick Perley]

    Some free time available this morning, took a look at antenna 21. 

    P-Band:  No fringes from any IF. 

    L-Band:  Fringes seen on all IFs, but very weak.  On AC, low by a 
factor of ~20 in amplitude.  On BD, low by a factor ~ 5. 

    C-Band:  No receiver.

    X-Band:  Stable fringes on all IFs.  The AC side has two amplitude 
states:  three consecutive low values (at 0.416 sec integration each), 
followed by one high value (so there is a 1.67 second periodicity).   
Sensitivity in the 'high' state is low by a factor of a few.  This is 
thought to be a problem with the L302, and a change is being made today. 
                On the BD side, good strong stable fringes.  Sensitivity 
still low by a factor of about 2, however.   

    K-Band.  No fringes.  Terrible weather too.