[RFI] Raspberry PI / Wall wart RFI

[Dave]

They recommend 2.5 amps for a Pi4

Dave wo2x

Sent from my waxed string and tin cans. 

> On Apr 2, 2021, at 10:33 PM, N4ZR <n4zr at comcast.net> wrote:
> 
> Jameco has a bunch of 5 and 12-volt linear wall warts for quite reasonable prices.  For example, their 5V unregulated 800 ma wall wart is $3.90, and a 12V 2 amp unit is $13.95.  There are a lot in between.
> 
> 73, Pete N4ZR
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> 
>> On 4/2/2021 8:49 PM, Jim Brown wrote:
>> 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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>> 
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