[CQ-Contest] Fw: Computer RFI

[Paul T. Antos]

I also found 100%  improvement by using an LCD monitor. However, while
playing with my cheap portable SW reciever looking for line QRN in the
neighborhood, I came across a lot of garbage radiating right from the front
of the LCD screen. Not that the SW reciever is any great shakes on shielding
. I suspect these devices radiate a lot of junk anyway, but I don't hear it
on my rig on any band with any antenna ( lucky for me). Ditto for the
halogen lamp in the shack. I guess the rig does a lot more in keeping the
noise out.

Not so lucky on the power line QRN ...

Paul  WB2ABD


----- Original Message ----- 
From: "Mark Beckwith" <n5ot at n5ot.com>
To: <cq-contest at contesting.com>
Sent: Wednesday, December 28, 2005 12:39 PM
Subject: Re: [CQ-Contest] Computer RFI


> Various comments about shack RFI and computer monitors:
>
> > I found that switching video modes, even just
> > the refresh rates, can make a big difference.
>
> AND
>
> > The best fix is to use an LCD monitor
> > instead of a CRT.
>
> AND
>
> > changed it out for a LCD monitor this fall
> > and all the interference went away!
>
> For some reason, when I switched to flat screens I noticed an improvement
> too, but lately the RFI grunge is creeping back.  I believe the problem is
> lack of line filtering in the rectangular black switching power supplies
> that come with the flat screens.
>
> To start, tho, I cleaned up a BUNCH of computer RF CRAP in my shack by
> adding commercial AC line filters to the computers themselves, at the
> recommendation of W0UN et al.  Go look at eBay auction # 7575746113 to see
> what I'm talking about - these come in various current ratings, but all
> pretty much look the same.  They come up on eBay all the time and are
pretty
> cheap and easy to install.  You basically open up the power supply and
> de-install the standard 120VAC jack and stick this in its place (hopefully
> it fits) and button it up and your AC is now filtered.
>
>> Mark, N5OT
>
> PS I have a large pile of these filters - I think I bought a lot of 38 of
> them on eBay and have used about 6.  I could part with some of them for $2
> each plus shipping.  Details on request.
>
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