Helping a friend with his RFI problem.
He has a SDR HF radio and Hustler BTV antenna with a toroid choke and about 32-radials. He has vertical bars on his panadaptor around 20 khz apart, mainly on 40M.
Disconnecting the antenna at the radio-end the bars go away, unscrewing the PL-259 so only the centre-pin is connected the RFI is mostly gone, fully connecting the PL-259 the bars are there.
Disconnected the coax at the antenna end, bars are also gone (thus i don't think this is common-mode RFI on the coax).
We've deduced his RFI is getting into his system from a radial wire ran under the BTV with RFI coming from a neighbours device (he's going to disconnect bunches of radials to triangulate which neighbour is the source of the RFI).
As this RFI is entering the system from a wire (radial(s)) and transported inside the coax, rather than the outer-shield, is there anything he can do on his equipment to remove this RFI?
As far as i know, the only solution would be for him to track the noisy device and put some ferrites on them, assuming a compliant neighbour. Did i miss anything?