Topband: RE: [RFI] Antenna Suggestions for 160 Noise Sniffing?

Cortland Richmond ka5s at earthlink.net
Sun Apr 4 10:08:49 EDT 2004


Mike, 

Don't make it TOO sensitive.  When noise is particularly loud (remember the
3.52 Hz Phonex modems?) I found that a small nonresonant loop mounted on a
handheld receiver (I used an AOR-8000) worked well once the neighborhood
had been found. I could"sniff" out the rooms from which the QRM was coming.
My best loop for this work, at this frequency range, was the low-frequency
handheld loop from an Empire RFI probe set, so heavy it was safer to let
the radio hang from it, rather than the other way around. And this is much
more so with smaller radios like the VR-500   For higher HF frequencies (or
much closer in) a loop made from about six inches to a foot or so of coax
works well, too.  Of course a ferrite loop will work fine -- but you may
not have to go to the trouble.  

Cortland


> [Original Message]
> From: Michael Tope <W4EF at dellroy.com>
> ...
> neighborhood and sniff for the QRN. Can anyone recommend a
> good portable antenna design that will have a good enough null
> that I can use it for DFing this noise. I was thinking that a ferrite
> rod antenna would be a good choice. If so, where can I find design





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