[ICOM] Display interference issues

[Frank N. Haas]

How interesting that this topic comes up now. For years I've been putting 
up with birdies and buzzes on the higher frequency HF bands that I knew was 
caused by the computers in my shack. I have two PCs very close to my Icoms. 
I was working 20 meter CW Sunday and decided that enough was enough. Thus 
began my search and destroy mission.

When the smoke cleared, I had found that my primary PC was radiating QRM 
via its video output and one of two displays were creating serious QRM. I 
eliminated the PC-radiated buzzing by wrapping an entire 7 foot long VGA 
extension cable around the ferrite core of an old TV yoke (trashed TVs are 
useful for something!) The choke hangs off the back of the PC tower.

The QRM caused by my 19" conventional CRT display could not be eliminated 
using any typical external technique. I had no interest in opening the 
display and modifying it. I decided to make my second PC display, an NEC 
LCD1712 LCD display my primary display. With the LCD display and "choked" 
VGA output all birdies and buzzes were GONE!

The LCD display did not produce any QRM by itself.

The second PC does not generate any QRM by itself. It's a bit newer and has 
an integrated video adapter vs. the separate video adapter of the primary 
PC. The second PC now has the noisy CRT display (for only a few more days!)

I placed an order with an online vendor for a new Samsung 19 inch LCD which 
should be here in a few days. Until then I only use the second PC as needed 
to keep the QRM manageable. The 19 inch LCD will become my primary display 
and the 17 inch display will go back to its original machine.

Meanwhile, the bands are quiet and the Icom receivers are happy.

73,

Frank N. Haas KB4T
Florida