[evlatests] Frequency mislabelling

[Rick Perley]

    Michael took a full 1 GHz spectrum at L-band, using 8 subands of 128 
MHz each, a day or so ago.  This allows me to check if the frequencies 
are right, as we have many 'beacons' in that passband. 

    It's very clear that the frequencies, as reported by AIPS, are off 
by one half of one channel:  The radars at 1030, 1090, 1310, and 1330 
MHz show up as 1030.25, 1090.25, ...  MHz

    Looking at the header, I note that the central frequencies of the 
subbands are listed as:

    1052.25, 1180.25, 1308.25 ... MHz. 

    Presumably, all of these are too high by 250 kHz.