[RFI] Interfering signal on 40 meter

[Jim Brown]

On 3/21/2024 12:58 PM, Chuck Gooden wrote:
> You will have to post a lot more details here like a waterfall from 
> HDSDR or some other SDR receiver if you have one.

The HDSDR suggestion is a very good one. Using a wide spectrum and 
waterfall may show something related on other frequencies. I've seen 
signals a bit like this that strongly suggest that they're leakage from 
some sort of electronic system. I've never bothered to try to track them 
down. Any signal that's stable (not drifting) and with no FM noise 
modulation is very likely coming from a microprocessor.

NK7Z has done some excellent work and developed some very useful 
procedures using an SDR as part of chasing RFI.

> If you can turn off all of your breakers in your house or apartment and 
> run the radio on battery.

Yes, but make sure that there isn't a UPS keeping some stuff on, AND 
causing noise itself. :)

Just curious -- what kind of activity takes place around 7103? The only 
times I've tuned around there have been activity stretched up to there 
in a CW or RTTY contest.

73, Jim K9YC