[RFI] Does anyone recognize this RFI?

Jim Brown jim at audiosystemsgroup.com
Wed Apr 15 13:27:05 EDT 2020

On 4/15/2020 9:48 AM, K9MA wrote:
> Looks like a switching power supply running at 55 kHz.

Unlikely. SMPS are free-running, modulated by noise, so they are "humps" 
of noise that drift. These signals are stable in frequency with no 

73, Jim K9YC

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