[CQ-Contest] CQWWSSB weird noises on 10 M and other bands
k9yc at audiosystemsgroup.com
Tue Nov 1 20:55:31 EDT 2022
On 11/1/2022 3:38 PM, kq2m at kq2m.com wrote:
> The other type of noise was what I'll call a "Squiggler" which was loud
> and about 3 - 5 khz wide.
You may be hearing high order harmonics of the square waves in a
switch-mode power supply (SMPS) which are ubiquitous -- there are at
least a couple of dozen in the typical US home -- or some power control
electronics, like a variable-speed controller for a motor.
Study this applications note, which ran several years ago in NCJ as a
two-parter. It provides lots of ideas about figuring out the type of
noise you're hearing, how to find the source, and how to kill (or
reduce) the noise.
73, Jim K9YC
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