[evlatests] Frequency Tuning at L-band

[Rick Perley]

    Michael et al. arranged to observe our 'standard L-band interferors' 
with 125 kHz resolution. 

    He provided me the correct tuning values, stating that these 
corresponded to the bottom edge of the first spectral channel. 

    With this, I find that all the standard interferors are located 
exactly 188 kHz too high (that is, 1.5 channels). 

    If, for some reason, the canonical frequencies correspond to the 
midpoint of the lowest channel, then all interferors are 125 kHz -- or 
one full channel -- too high. 

    Note that in the earlier experiment, with 500 kHz resolution, the 
offset was 250 kHz -- one/half of one channel (using the interpretation 
that the sub-band frequency listed corresponds to the center of the 
first channel).