New RFI - 24khz spacing on 80m

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Joined: Sat Feb 13, 2021 6:23 pm

New RFI - 24khz spacing on 80m


Unread post by raydeeoh »

Hi all,
Wondering if anyone has seen anything like this before and, if so, what is the likely culprit. I was away for two weeks, came home and turned on the radio to find this wonderful new noise all across 80/75m with approximately 24khz spacing between signals.

I'm using a Hermes Lite 2, powered by a 12v battery, not connected to house mains at all. I've shut down everything that is connected to the house mains in the shack and still see the same signals.

Any advice/direction is greatly appreciated!
Robert VE7ZN

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Posts: 212
Joined: Tue Aug 11, 2020 2:16 pm

Re: New RFI - 24khz spacing on 80m


Unread post by KA1GJU »

Looking at, you have two immediate neighbors that could have a SPS (Switching Power Supply) running a cordless screwdriver, charging batteries in a UPS, or ??? Any UPS's in your QTH? Or one attached to your Internet connection from street. We have fiber to the house, but the converter box has a battery and charger to keep phone/Internet up during power outages.
To check if it's your USB cord, place a small whip antenna on the feedline and sweep the USB cord. An open ground on a USB cable made me chase my tail for a few hours on SDRC Superstation #1. But it made one heck of a mess of the spectrum!

How big is the antenna and how close to which neighbor?

73 Kriss KA1GJU

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