[RFI] A new source of QRM

[Jim Brown]

On 1/24/2026 6:01 PM, Don Moman VE6JY wrote:
> all switch mode noises...chargers, inverters etc. almost anything that
> plugs in.  But it's not powerline arcing or that type...

Right. On an RF or IF waterfall, horizontal lines are impulse noise 
(lightning, arcing), vertical lines are electronically generated.

Tutorial here about how to find sources, both in your home and at a 
distance, and how to kill the small ones with ferrite chokes. It's for a 
talk I did in 2017 at the Visalia DX Convention, and the waterfalls were 
done with the Elecraft P3 fed from a K3 IF.

http://k9yc.com/KillingRXNoiseVisalia.pdf

73, Jim K9YC