[evlatests] Test of RFI Blanking at Pband

[Rick Perley]

I've noted in earlier posts about the 'flickering' RFI that we commonly see at P-band.
We ran another P-band test yesterday afternoon, with the 'RFI Blanking' turned on, to see if this would remove the observed effects (most a small gain compression, lasting typically 5 to 12 seconds).

Perhaps unsurprisingly, it did not.  The cause of the problem is likely too slow in time to be caught by the on-line flagging.  The durations of the observed RFI 'flickers' and accompanying gain compression is typically 5 to 12 seconds.



Other notes:

ea21V is still low in SNR by about a factor of 10.  It also has a sinusoidal bandpass shape, indicating a strong reflection in the signal chain.  The period of the reflection is 3 MHz, indicating the reflecting points are about 50 meters apart (free space equivalent).  So the problem is in a long cable.

The gains in ea11 show an  SNR down by about a factor of 2, in both polarizations.




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