[RFI] "Fake" power supplies

[Dale]

All,

In view of the continuing multiple threads regarding RFI to radio systems from various products and their power supplies, here is an article that I think sheds some light on the severity of the problem we, and others who need to communicate via radio, are facing in today's world:

http://www.edn.com/electronics-blogs/power-supply-notes/4409903/How-to-avoid-being-ripped-off-when-buying-power-supplies

Note: You will need to copy and paste, since plain text does not support active links.  Once you get into the article, be sure to click on the link that takes you to the discussion about the fake PFC ("power factor correction") coil.  I was stunned, and angry, as well.  Visions of correcting that problem via K9YC's "Bucket Treatment" come immediaetly to mind.

Frankly, while I had seen el sleazo power supplies that probably once had all parts in place (long enought to pass testing) and then the EMC components were deleted so as to save 50 cents or so per unit in production, I have not run into actual fakery as described in this article.  It is bad enough when some piece of electronic equipment that you own has junk like this inside, but when it ends up in something owned by your neighbor. then the REAL problems set in. After all, when you end up with a bad switching supply, you can at least throw it in the trash and probably replace it with a homebrew (or maybe surplus) linear model that will not affect your ham operations.  When your neighbor gets this stuff, it's bad news unless he/she can be convinced to complain to the seller or manufacturer that it causes interference (per Part 15) and maybe get some response from the FCC (not likely, but maybe).

A point to keep in mind is that reputable product manufacturers may very well be selling products that are powered by garbage like what is discussed in this article.  (Note the comments about fake UL and FCC labels.)  If they do not conduct full EMC tests on the selected product (and most probably will not), then the only way that a bad choice in power supply vendor will be known is when someone who is sensitive to RFI issues gets burned and yells, a lot.

73, Dale
WA9ENA