[RFI] DC Power supplies

WD8ARZ wd8arz at ix.netcom.com
Wed May 4 17:14:27 EDT 2016

AC switching type power supplies tend to be very rfi noisy. Transformer 
type power supplies dont use the the dc to ac to dc switching that 
generate that RFI ....  and should be quieter power supplies. They are 
heavier, with line isolation in most cases, and worth the extra expense 
and weight. Another bad trait for those switching power supplies is that 
there is generally not a true physical break the utility power feed 
switch. Instead they just disable the output and leave the switching 
circuits active and thus are RFI sources as long as they are plugged in.

73 from Bill - WD8ARZ
South Bend, Indiana

On 5/4/2016 2:51 PM, charlie at thegallos.com wrote:
> Hey Gang,
> We all know about buying old analog wall warts for power supplies to cut
> down on RFI, but sometimes, that is NOT going to happen
> snip snip
> I think it might be a real good idea if we could come up with a list of
> various "Line lump" (so they can be wired in) type power supplies at
> various power ratings that are KNOWN to be good, and sources for them
> I'd be more than happy to collect the list and put it up on my web site
> 73 de KG2V - Charlie - www.thegallos.com

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