[evlatests] More on Wideband Modes

[Rick Perley]

    Ken took three short tests utilizing the wideband setups.  The three 
were:

    a) Four subbands from IFpair A/C, each of 128 MHz, full 
polarization, 64 channels/spectrum. 
    b) Four subbands from each of IFpairs A/C and B/D.  128 MHz, full 
polarization, 64 channels/spectrum.
    c) Eight subbands from IFpair A/C, each 128 MHz, full polarization, 
64channels/spectrum.

    In short, all worked well.  There are a few common peculiarities:

    1)  Antenna 12 never gave any fringes from IFpair A/C.   It did from 
IFpair B/D.  This looks like a failure to tune, but other explanations 
are likely.  The data were not flagged -- just noise. 
    2) Antennas 2, 4, 11 and 27 were flagged out in tests (a) and (b), 
but provided perfectly good data from test (c).  From this, I would 
deduce the antenna is fine, and the flagged data were from some other 
cause.  (I'm filling the data as unflagged now, to see if the problem is 
'zeros', or something like antenna not on source, etc.  
    3) Antennas 14, 15 and 16 were flagged in both polarizations from 
subband 4 in all three setups.  This cannot be an antenna problem, as 
the other subbands were always fine. 
    4) Antenna 18 gave no fringes from IFs B/D.
    5) Antenna 26, in LCP, gave noise in IFs 2 and 8, independent of the 
originating IF.  This is again not an antenna problem. 
    6) Antenna 13 never gave any fringes (it has no receiver) -- and was 
incompletely flagged -- sometimes flagged, sometimes not.