[RFI] VHF DSSS?

nlsa at nlsa.com nlsa at nlsa.com
Thu Nov 17 10:15:32 EST 2022


Dear friends,

A new source of interference popped up a few days ago.  Its center frequency
appears to be 143.950 MHz with sidebands every 200 kHz up and down the
spectrum.

It is intermittent but when present it is solid and steady in amplitude and
frequency.  It might be present nearly continuously for hours, or hours may
pass with nothing.  There doesn't appear to be any audio or video
modulation; listening on NBFM yields a steady whoosh like wind.

Does anyone recognize the waveform?  DSSS comes to mind.  My EME antenna
peaks exactly in line with a QRO TV transmitter site about 10 km
line-of-sight distant but its engineer (a sympathetic ham) doesn't know what
it might be.

Ideas welcome!

73,

Mike, W9IP

 



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