Tuesday, January 19, 2021

HF noise at my home

Since moving to our smaller home in Thornbury I've been observing the noise on HF. It varies widely. Sometimes, 40m has broadband S9 noise.

At other times it's pretty good.

Sometimes the noise appears to be from a switching power supply (and this pattern is repeated all across HF!)

20m can be pretty good at times.

Yesterday I had a good voice contact with Ray, VK2ELO. One thing that stands out is, what I presume to be, over the horizon radar. Normally pretty narrow but this one sweeps more than 250kHz.

The noise canceller I built can work on the switching noise but can't help with broadband noise. Sometimes the most practical way to do ham radio from a suburban home is to transmit locally and receive via a near by WebSDR.


Richard said...

Hi Peter, hf noise is the modern curse.
I'm sure you are on top of this, but, have you tried operating off battery and turning off the house power?
Another is if you have good common mode Baluns on the antenna feeds at the antenna and the transceiver?

Peter Marks said...

Hi Richard,
Yes, I did turn the house power off early on and that's not a major source. I think the neighbours have a charger for power tools that makes the switching hash - it seems to coincide with them doing woodwork.
There's probably more to do with antennas for sure.