[RFI] Fwd: Undelivered Mail Returned to Sender

[Michael Coslo]

This is kind of like the LED or CFL bulb debates, where someone finds a poorly designed one, and it somehow morphs into calls for avoiding every single one.

I test every one of my wall warts. Of the dozens I use, I only found maybe two that had an issue. They were tossed. And some are very difficult to avoid, like say a phone charger. My little iPhone chargers are nice and quiet. My Maestro uses an MW switcher. It’s quiet, and my Alinco Switcher is quiet on any Ham bands. I did a video on that one, The only place that spikes start showing up is in the BCB, and they are tiny. Otherwise, there is no difference between in and the linear transformer I also use. Rather than wholesale avoidance, it’s easy to find out which ones are a problem.

- 73 -
- Michael Coslo -
Frequency Coordinator, Beaver Stadium
814-404-3991
mjc5 at psu.edu
mjcn3li at gmail.com

> On May 4, 2019, at 8:40 PM, Roger (K8RI) <k8ri at rogerhalstead.com> wrote:
> 
> Switch mode power supplies and Pulse Width speed controllers can be made that do not radiate noise, but they cost more so those parts are often left out saving maybe 10 to 50 cents on the construction.  With the many millions of wall warts this can add up to millions of dollars in profits.
> 
> Like Jim, I say it's best to avoid them.