[evlatests] 4-band results

[Rick Perley]

    Curiously -- the situation at 4-band seems much better than at 
P-band (although perhaps our criteria for success at 4-band are quite a 
bit different than at P!)

    In general, all polarizations seem to be correct.  Phases are good 
in general. 

    *  Antenna 12 gives no fringes, but is not flagged.

    * Antenna 24 flagged on all IFs -- but works o.k. in IF#2 (B and D). 

    * antennas 13 and 16 are correctly flagged out.  (Curiously, I see 
stable fringes on antenna 16, but they don't close correctly, so 
represent some other sort of coherent signal). 

    * Antenna 26D gave both multiple phase and amplitude levels.  I 
think this should have been fixed by Mike, and a test should be done to 
see. 

    * Antenna 28 gave the same 1.25 phase ramp on all IFs that I saw at 
P-band -- only this time, the ramp took place in the FIRST 10 SECONDS of 
the scan.

    * Antenna 18, IFs A and C had a bistable phase throughout (5 
minutes).  The same situation as in one of the P-band scans. 

    * Antenna 4A and 4B (RCP) is a factor of 3 low in amplitude. 
    * Antennas 11 and 19 are low by a factor of 10 in amplitude on all 4 
IFs.  (Tcal?) 
    * Antenna 18, IFs A and C are showing 'short shallow drops'.  No big 
deal.
    * Antenna 17 is quite erratic in amplitude on all IFs.   A and C 
behave identically, IFs B and D also, but different than A and C.
    * Antenna 20B is very erratic in amplitude.
    * Antenna 23 A and C is erratic in amplitude.
    * An
tenna 24 A gives no coherence, and 24C very weak and variable 
coherence.  But 24B and D look fine.  All four IFs were flagged.