[RFI] Noise Level During Power Outage

[Pete Smith N4ZR]

How about a big dose of 60 and 120-buzz?

73, Pete N4ZR

On 2/1/2023 3:33 AM, Jim Brown wrote:
> On 1/31/2023 9:21 PM, K9MA wrote:
>> My QTH is in an older residential area, surrounded by overhead power 
>> lines. Line noise is a constant problem. We recently had a major 
>> power outage, so I measured the noise levels to get a baseline with 
>> little line noise.
>
> Hi Scott,
>
> How do you know that it's line noise, not electronic noise? 25 years 
> ago, line noise was a good assumption for anything we heard on the 
> bands, but in almost any developed area, the average home has a couple 
> of dozen electronic sources, everything from switch-mode power 
> supplies for everything that plugs into the wall, variable speed 
> controllers for motors, computers and lots of other stuff with 
> microprocessors in them, and on, and on. When the power goes out, so 
> do all of those electronic noise sources (except for those that UPSs 
> keep running).
>
> The slides for talks I've done at Pacificon, Visalia, and to some 
> clubs, show how to use a well-adjusted waterfall to differentiate 
> between impulse noise (which is what line noise is) and electronic noise.
>
> http://k9yc.com/KillingReceiveNoise.pdf
>
> Yes, those with ear experience can nearly always tell the difference.
>
> NK7Z has wonderful advice and resources on his site about using 24 
> hour very wide waterfalls to yield clues about operating hours of both 
> impulse and electronic sources, and also recognizing multiple 
> electronic sources.
>
> 73, Jim K9YC
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