[evlatests] Antennas 3 and 7 -- Modcomp-Free

[Rick Perley]

    I have previously reported that antennas 3 and 7, when under 
Modcomp-Free operations, give essentially no correlation.  I also noted 
on Sunday that the bandpass phase seems to alternate by 180 on adjacent 
channels. 
    Upon closer inspection, it is quite clear that the two antennas have 
a *humongous* delay error:  They fringe beautifully against each other, 
with a (relatively small) differential delay of ~85 nsec.  Intepreting 
the phase oscillation as a delay error sufficient to rotate the phase by 
1/2 turn for every channel (separation of 780 kHz), we find a delay of 
~650 nsec.  I can't tell the sign.