[RFI] Raspberry PI / Wall wart RFI

[Jim Brown]

That's because it's a switch-mode power supply. What voltage and 
current?  Depending on that, it may be possible to re-purpose an old 
linear wall wart. Also, study my tutorials on chasing and killing RFI. 
They include specific advice on subbing the linear supply.

Text:  http://k9yc.com/KillingReceiveNoise.pdf
Slides: http://k9yc.com/KillingRXNoiseVisalia.pdf

73, Jim K9YC

On 4/2/2021 5:15 PM, David Gottschalk wrote:
> I'm wondering if anyone has had success finding a wall wart for a Raspberry
> Pi that doesn't make horrific RFI on HF (or really any switch mode power
> supply that isn't noisy!)
> 
> I recently discovered the wall wart for my Raspberry PI (that is mounted
> outside in a water proof enclosure for my 4G internet) is making S7 level
> noise on 80m. Unfortunately, my 80m loop is currently pretty close to it.
> When the PI is battery powered, or off, it's S4 noise level here (This is
> in the middle of the day). 60m also seems to be severely affected as well.
> 
> I found this on Amazon, but it seems like it's more of a AC line
> conditioner, but might be worth a shot. Any feedback would be greatly
> appreciated.
> 
> https://www.amazon.com/iPower-Supply-International-Travel-Adapters/dp/B01GNNXP0Y?ref_=ast_sto_dp&th=1
> 
> 73,
> David
> KN4ZKT
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