[evlatests] Other notes from yesterday's short test

[Rick Perley]

 In talking with Ken, I learn that two of the issues raised below have 
been resolved, or are understood.  To save him the trouble of replying, 
here is what I think I learned:

>     3) The bandpasses all look very nice, with one curious exception.  
> Sub-band 4  (1372 to 1404 MHz) shows a notable roll-off on its low 
> frequency edge, in both polarizations and on all antennas.  The other 
> subbands show a sharp cutoff at both ends -- dropping about 5 dB in 2 to 
> 2.5 MHz.  For subband 4, the frequency span for this drop is about 10 
> MHz.  The upper edge has a normal cutoff. 
>   
    This is a feature.  The data were taken with two filter stages.  The 
first is the 128 MHz-wide filter, the second the 32-MHz-wide filter.  It 
turns out that the fourth subband in the data taken yesterday was on the 
low-frequency edge of the first-stage filter. 
>     4) Antenna 9 has a temporal phase wind of 1.5 degrees/second, in LCP 
> only.  RCP is steady.  All other antennas are 'rock-solid' in both IFs. 
>
>   
    The phase tracking was turned off for some reason (probably a 
test).  Ken has turned it back on.