Topband: Computer RFI on 160

[Paul Kelley N1BUG]

Bill Tippett wrote:
> Although the 6EF1 lists for ~$15 each from normal distributors, I see
> someone on eBay is selling them for $75/10 units.  I've seen them for
> sale at lower quantities and prices so you might watch for some to
> appear.  Having a few of these in your junk box for emergency RFI
> fixes might be a good idea.

I couldn't agree more! I have solved some nasty RFI problems in my 
own home using Potter & Brumfield 611G3E / 611G6E filters. I picked 
up these modules at a swap meet for something like $1 each!

At one time I had a computer power supply that was producing S9 plus 
noise right in the middle of the DX portion of 160m. It was a broad, 
unstable growl, characteristic of switching power supply noise. 
Putting one of the P&B filters on the computer took it down below my 
noise floor which runs about S1.

I also have some Corcom 6J4 filtered power entry modules which I 
find very effective.

I use one or the other of these filtered power entry modules on any 
homebrew shack accessories that are powered directly from the AC 
line. I'm not sure this helps anything, but it can't hurt.

73,
Paul N1BUG