[RFI] Dancing Carriers

[Jim Brown]

On 12/19/2022 1:04 PM, k1ttt.dave at gmail.com wrote:
> Signals like that which move up and down are generally something like
> harmonics of switching power supply or variable speed motor or some other
> non locked frequency digital system, that is, something that doesn't rely on
> a specific clock frequency like computers, tv's, modems, ethernet, etc
> require.  

Every one of them that I've seen is frequency-modulated by noise, so in 
addition to drifting, it's a band of noise. And this is at 2M.

> Power supplies drift with temperature, line voltage, or load.  The
> step functions you see may be because the sdr only processes the spectrum a
> few times a second so they appear to stay the same for a short time then
> jump a bit as the next set of samples is plotted and the signal has moved
> into the next fft column range.

Maybe, but I'd like to know what this noise sounds like.

73, Jim K9YC