[evlatests] Strong or Pulsed RFI in X-band

[Rick Perley]

     My Hydra A, D-configuration X-band data shows some interesting RFI.

     1) All frequencies above 11454 MHz (to 12000) are completely 
obliterated by wideband RFI.  This is clearly a geostationary set of 
satellites -- the 3C286 calibration data are only slightly affected, 
while all of Hydra A (dec -12, and the calibrator, dec -14) are wiped 
out.   These satellites must be VERY strong, as we are quite a distance 
(in beamwidths) from the center of the satellite belt (dec -5).

     2) A curious (but not strong) comb of RFI showed up in one scan, 
lasting about 15 minutes.  There are six 'lines', located at 9550, 9610, 
9770, 9830, 9890 and 9950 MHz.

     3) There is a long-runnning, pulsed pair of signals at 9368 MHz.  
The pair are separated by 6 seconds, and the pulse period is about 33 
seconds.

     4) Weak RFI is at 9338 MHz.

     All else between 8 and 12 GHz looks very clean.