Although my computer affects certain frequencies a little bit,the coax fed
outside antenna to my DX392 helps.

For my little radios I carry around the house (B&H, jWIN, eTR7), I have to turn
off my monitor. It's a Proview and should be required to have an FCC license as
a transmitter.

I had a strange problem, regarding my little radios. Although my computer and
monitor were on, there was no noise interferring with the stronger SW stations.
Then I plugged in my modem line to the phone circuit. (I had it disconnected
because of nearby lightning strikes.) This was at the opposite end of a long
run from the computer. The monitor noise was loud. Apparently, with the modem
line unloaded, there wasn't much radiation, despite the line running past the
little radio in use at the time.

73,
Bill, K5BY