[RFI] Investigating receive noise - got a few questions

[Michael Coslo]

It seems to be a popular thing to condemn every switcher as noisy. Whenever I purchase something that comes with a wall wart, I check it out with my radio on all bands. Most pass. 

What is more, if we willy nilly replace the dreaded switchers with the linear, we could actually cause problems where one did not exist. 

Being built to be cheap, the linears I have seen have a transformer, a full wave rectifier, and a filter cap. My experience with Linear wall warts echos this http://www.dxing.info/equipment/wall_warts_bryant.dx 

If an Op wants to have no switchers, and if they want clean power. make a power distribution system with a well regulated, properly filtered power supply, and not allow a wall wart to be seen in their house. 

But really, check out that switcher before trashing it. You aren’t gaining a lot by going to a cheap linear wart, and might introduce problems. 



- Michael Coslo -
Frequency Coordinator, Beaver Stadium
814-404-3991
mjc5 at psu.edu
mjcn3li at gmail.com

> On Nov 28, 2018, at 11:14 PM, Roger (K8RI) <k8ri at rogerhalstead.com> wrote:
> 
> One thing to keep in mind and this list seems to ignore. Not all switching supplies generate noise although many, if not most do.