Power cord placement will probably not make much difference on higher HF 
frequencies.  Is your monitor on when this happens?  If this is a desktop, 
what happens if you temporarily disconnect the keyboard, the mouse, the 
ethernet cable, etc.?



Lloyd Rasmussen, Kensington, MD
http://lras.home.sprynet.com
-----Original Message----- 
From: Tom Behler
Sent: Friday, November 15, 2013 8:30 AM
To: [log in to unmask]
Subject: Anoying Interference Issue

Hi, all.

As I think many of you know, I am currently in the process of switching to a
Windows 7 PC as my main home computer.  I will be using the PC for both
professional and personal purposes here in my home office.

My home office is also where I have my ham station set up, which does have
its advantages if I need to take a little break and check out the bands
every once in a while.  (grin)

Anyway, I have just noticed that when this new computer is running, it
places all sorts of little birdies across the HF bands, particularly the
higher HF bands like 10 and 15 meters.

To me, this obviously means that the computer has a very poorly-designed
switching power supply.

My question is what might I be able to do to minimize this interference?

I have thought of switching the computer to another circuit in the house,
but that would involve running an extension cord into another room, which
could be a bit of a pain.

If there is a fortunate side to this dilemma, it is that I am not going to
be using the PC for ham radio applications such as logging, rig control, and
the like.  Those functions are done via a separate Windows XP laptop that I
have on my ham radio operating desk.

Of course, the obvious low tech solution to this issue would simply be to
turn off the main PC whenever I am operating on the HF bands, and I may have
to resort to that for now.

If, though, there is something else I might want to try, please let me know.

Tom Behler: KB8TYJ