[evlatests] PBand is Alive! (sort of ...)

[Rick Perley]

    Ken took some P-band data yesterday and today, essentially to see if 
the P-band signals get along with WIDAR ...

    Yesterday's data were taken with two 128-MHz subbands, centered at 
352.0 MHz in both IF pairs, with 2 MHz-wide channels, and full 
polarization.  He anticipated that the spectra would be reversed, and he 
was right -- to get the right frequencies, the frequency axis (or the 
spectra) need to be inverted about the midpoint. 
    Today's data were taken with 64 MHz-wide subbands, centered at 320 
MHz, with the frequency axis now thought to be correct.  He later 
reported that it was likely the correlator was not working at the time 
of the test -- and he was right again. 

    This report is based on the first test only. 

    *  12 antennas are fringing well:  2, 8, 11, 13, 17, 18, 19, 21, 23, 
25, 26 and 28.  Two antennas gave weak fringes:  15 and 27.  Antennas 
10, 12 and 20 were out of the array.  Antennas 7, 16, and 22 do not have 
receivers.  Antenna 24 has no feed.  Antennas 1, 4 and 5 are listed as 
having receivers installed, but not working.  That leaves four antennas 
which might have been thought to work, but do not:  3, 6, 9, and 14. 
    *  The polarizations in antenna 17 are reversed.  (Fortunately, 
there is a nifty AIPS task which fixes this easily). 
    *  Delays are reasonable -- the largest is about 40 nsec. 
    *  Bandpasses are as expected:  The 10-db points are near 300 and 
345 MHz.