SV: [ICOM] Display interference issues

[N9QQB]

Additional comments at bottom-
At 10:33 AM 4/5/2005 +0200, you wrote:
>About your birdies from the CRT I have found out the same thing. I have to
>replace them with flatscreens and a number of chokes as well. That solved
>it.
>I had an very old CRT that was noicefree, but that one died. When it died I
>opened it and found  that it was totally screened with metal inside the
>plastic cover.
>Open one of the newer ones and see!!! No screen at all .........
>
>When I bought the the new flatones I made a deal, that if they made birdies
>I could return them and get the money back  Nice
>
>73 de Mats
>
>-----Ursprungligt meddelande-----
>Fran: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net]For
>Frank N. Haas
>Skickat: den 4 april 2005 18:15
>Till: icom at mailman.qth.net
>Amne: [ICOM] Display interference issues
>
>
>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.

My Benq Fp951 doesn't seem to radiate anything. My 5-port ethernet switch, 
on the other hand sprays RF all over the place.

What I'd like to see someone try is to take the plastic housing off a cheap 
monitor that causes birdies and spray the inside with many thin coats of 
some sort of paint with lots of metallic content. Maybe a chrome, brass, or 
copper colored spray paint from the hardware store has actual metal in it. 
I wonder if it'd work.

Since the paint would probably overspray around the edges and through the 
grille, you'd have to be willing to mess up a working monitor, or else 
spray a finish coat on the outside when you're done.







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