[Elecraft] PC and video monitor QRM...

[Steve Banks]

Hi Everyone

Does anyone have any suggestions about possible ways to reduce QRM affecting
a K2, which is likely coming from my nearby video monitor and/or PC, which
are both AC-operated?

Awhile back I think I read a post answering a similar question, which
suggested installation of split beads of some type for the ends of the PC's
AC supply cord.  It may have also recommended similar treatment for the
video card's signal line which connects to the monitor; however, the details
of the post escape my memory.

In my case, the K2 and PC (and its monitor) are separated by about 3 to 4
feet without extra shielding of any sort, except for the RF case covers on
the PC.

The QRM is worst on 20m.  (Naturally, that's where I sped a lot of time.)
It's not terribly bad, but it definitely seems that the PC and/or monitor
are the QRM source.  The interfering signal is a bothersome audible AC hum.
It tapers off significantly (essentially disappears) on the bands above and
below 20m with the PC and monitor turned on.  When the PC and monitor are
turned off, the noise diminishes on all bands (especially 20m) by about one
S-unit compared to when they are both turned on.

If anyone has suggestions, please feel free to write either via the
reflector or directly to me.

Tnx es 73,

Steve Banks
K0PQ
K2 S/N 1599