[evlatests] Antenna Data Quality

[Rick Perley]

    In preparation for the annual 'flux density run', I'm carefully 
reviewing antenna performance at all bands, and various frequencies. 

    From last night, I find the following issues:    (All antennas were 
in the array)

    P-Band:

No fringes from antennas 1, 4, or 5. 
Very weak fringes on 21A, 26A, 26B, 18C, 18D, 3C, 3D. 
No switched cal (or a hugely erratic switched cal) on antenna 21. 

    L-Band:

Very weak fringes on antenna 5, all IFs. 

    C-Band:

No fringes from antenna 21, all IFs.
Very weak (low by a factor of 100) fringes from 25, all IFs. 
Antenna 3, IFs B and D, failed to tune on two scans. 

    X-Band:

All antenna working as expected.

    U-Band:

All (remaining) antennas working well.

    K-Band

Antenna 11 gave no fringes on IFs A, B, or C (but did on D!)

    Q-Band

No fringes from antennas 3 and 5. 

There are various initialization problems (especially at K and Q bands, 
due to the 'subreflector rotation trick').