[evlatests] 128 MHz RFI comb in Q-band ...

[Rick Perley]

    The last time a full spectra sweep was run (March of this year), I 
found a remarkable set of comb-like interferors at the high end of Q-band. 
    The recent sweep shows these are still present.  They have 
interesting properties:
   
    1) They are visible only at the high end of Q-band.
    2) They are at integer multiples of 128 MHz (starting at 379*128). 
    3) They are present only on a few tens of baselines.  Antennas which 
have by far the strongest birdies are:  14, 21, 11 and 22. 
    4) These antennas are all near the center of the array (W3, E3, E1, 
and N2, respectively).  However, other antennas in this vicinity show 
very weak, or no, lines at all.  So I suggest we look first at these 
four antennas for an origin.