[evlatests] New RFI in Antenna 14!

[Rick Perley]

    I ran a 12-hour RFI check of antenna 14 last night 
(Wednesday/Thursday), using the 'FFT Spectral Scanner' of Mike's and 
Walter's.  The goal was to monitor the DME spectrum, to see if (as 
anticipated) the 1.05 -- 1.15 GHz spectrum opens up late at night. 

    8192-channel spectra (resolution of 250 kHz) spectra were taken 
every minute.  The results show a remarkable comb on RFI, *** which was 
not present in that antenna a few months ago ***:

    There is a comb of strong, steady interfering tones, with spacing 
62.5 MHz, starting at 1000.0 MHz, and extending all the way to 1940 MHz. 

    I was in that antenna today (as part of a tour), and noted -- with 
some surprise -- that the cover plate of the utility box was not 
attached!  I suspect that the comb I saw (plus a lot of other steady RFI 
in the spectrum) was emanating out of that gaping hole, from the 
considerable digital stuff located within. 

    Is this spectrum of RFI expected from the hardware within?