"OldSailor" wrote in news:LtKDg.67395$Uy1.34616
@read1.cgocable.net:

I have two spare fans - Will have to run them on the boat and see if they
too cause interference.




If they make RF noise, try wrapping the power wires around a ferrite core
you can buy at electronics shops and, now recently, computer shops. That
barrel-shaped bobble on your USB and power cables is a ferrite core inside
the plastic. Wrap a couple of turns of the power wires through the hole in
the middle and back around the outside through the hole, again. Do both
plus and minus wires simultaneously. It's called bi-filar winding. Isn't
that impressive?! The ferrite core makes an RF choke and the core absorbs
the RF energy before it gets to radiate from the DC wiring to the fan. put
this "choke" as close to the fan motor as you can get it, with the shortest
leads between the choke and the fan. Try it on the one that's noisy.

Some of the cores are in plastic carriers that come apart to make putting
the wires through easier. They work, too.


--
There's amazing intelligence in the Universe.
You can tell because none of them ever called Earth.