[evlatests] 4-band Troubles

[Rick Perley]

    We attempted to determine the state of the 4-band system this morning. 

    Unfortunately, at this time, the 'gold standard' source -- Cygnus A, 
is down, and the next-best source (Taurus A) is completely resolved 
out.  So we have to use 3C123 -- a mere 400 Jy. 

    The file consisted of alternating observations in continuum and 
spectral line (various modes:  2AC, 2BD, and 4). 

    No data from any of the spectral line modes made it to the archive!  
I don't know if that's because the vispipe/IDCAF connection has a 
problem, or if the correlator simply didn't produce any data. 

    The continuum data are all present.  However, no sensible coherence 
was seen on any baseline, on any scan.  Even with only 400 Jy, we should 
be able to discern phase coherence. 

    More work is clearly needed -- and we need to wait for Cyg A to 
rise, so we can get enough flux density to get a clear signal.