[RFI] DFing power line noise

Tom Rauch w8ji at contesting.com
Mon Jul 19 17:01:12 EDT 2004

With 2MHz  noise will periodically rise and fall with
standing waves on the line, and noise will carry for many
miles. Also a shield on the loop isn't necessary. The shield
only changes the loop balance and can actually make it worse
if implemented wrong, so you really just need to build a
proper loop.

What I have done is use a VERY wideband amplifier with a
broadband loopstick. If the noise is looked at least one
octave of BW, the peaks and dips largely go away making it
easier to drive up to the source.

I think it is better to use VHF or UHF, and only use HF to
"match" the noise so you know you have the actual problem

UHF TV antennas into a broadband amplifier and a UHF AM
receiver works great.

73 Tom

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