[Elecraft] QRP, DX ops, RFI, K2/100

[Brian Machesney]

PC CPU clocks are "spread spectrum" modulated to keep the RFI from being
concentrated on a single frequency. In the PC's case, the "spread
spectrum" effect is to simply vary the clock frequency, which
corresponds roughly to the width of the interference you're hearing. How
much does it "wander?"

Brian K1LI

On Thu, 5 Dec 2002, Wallace, Andy wrote:

> a challenge to anyone who lives in any kind of populated area. Right
now
> I am trying to track down a wandering signal which is 5 kHz wide and
> appears on 40 and 30m here -- fairly regular on 10.112. It's nothing
> in my place. It wanders up and down at random, sounding like a
swooshing
> wind through an opening. Does not sound like light dimmers or
switching
> supplies or like anything I'd heard before.


Andy,

That sounds JUST like the RFI I traced down to a PC.  You may want to
start there with your tracking.

73 de John - K4WTF