[evlatests] Today's Stress Test

[Rick Perley]

    I quickly ran through the 'stress test' run late this afternoon.  
All bands (except U) in line and continuum. 

    In general, things are in very good shape. 

    General Issues:

    Something is amiss with 26D --- the spectrum is all wrong.  I think 
this is a DCS issue. 
    Off-source flagging is fine. 
   
    Specific issues noted, by band. 

    1)  X-Band:

    Antenna 10 is flagged as bad, but the data look fine. 

    2) L-Band:

    In the continuum, antenna 13 was giving constant visibilities 100 
times too high.  These were not flagged. 
    In the spectral line portion (15 minutes later, following the 
8-minute gap), 13 was normal. 

    3) P-Band:

    Antenna 23 is still rising and falling -- Ken has explained the 
problem as a non-functional sync detector, so noise Tsys corrections are 
erroneously being used.  (Shouldn't we test on whether the sync detector 
voltage is at least plausible, before applying it?) 
    Antenna 26 gives no fringes (and is flagged as bad).  I swear there 
were good data from this antenna few days ago...

    4) C-Band:

    There was an 8 minute gap in the data (nothing reported in the log), 
starting at 23:41:44.  No c-band continuum data were obtained.  The data 
stream resumed when on X-band, at 23:49:00.
    The line data showed antenna-IFs 18C and 18D as flagged, but the 
data appear to be fine. 

    5) K-Band:

    Antenna/IF 13B is weak, and 13D gives no discernible fringes, and 
neither is flagged.   This is not a delay problem.  13A and 13C are 
flagged, but the data appear fine.  (I've reported this problem before). 
    Antenna 24B and 24D are flagged in continuum, but the data appear to 
be good .
    But in spectral line, it's 24C and 24D that are flagged (LCP), but 
the data are fine.

    6) Q-Band:

       Lots of troubles here ...

    Antennas 3 and 10 are flagged, but give good data. 
    Antennas 6, 20, 23 and 26 all giver very weak, or no fringes.  Could 
be a pointing issue, as the 'referenced pointing' scan went out with the 
8-minute gap, mentioned above. 
    Antenna 13B is weak, and 13D gives no fringes at all.  (Same as at 
K-band).