Hi Dale,
I guess that FCC Type Acceptance stickers that they put on these
things---the ones that say the item attached is not supposed to cause
intereference to other devices---are pretty well useless anymore...
There should be a "PS" added at the bottom of that sticker verbiage. to
whit: "THIS DEVICE IS ALLOWED TO READILY & FREELY INTERFERE WITH LEGITIMATE
LICENSED AMATEUR RADIO ACTIVITIES, BUT THE REVERSE DOES NOT HOLD TRUE." Hi
Hi
~73~ de Eddy VE3CUI - VE3XZ
******************************************
----- Original Message -----
From: "Dale Svetanoff" <svetanoff@earthlink.net>
To: "W4PV" <w4pv@comcast.net>; <rfi@contesting.com>
Sent: Saturday, November 13, 2010 3:41 PM
Subject: Re: [RFI] Plasma TV's
> Patrick,
>
> Ah, if only it were that simple. I could suggest that you borrow (or
rent)
> one of the new generation portable, battery-powered spectrum analyzers and
> take it with you when you shop, but in reality, it probably would only
> alert you to real "screamers" - those sets with lots of ugly radiated
> emissions. In the end, I believe (and suggest) that the best approach is
> to buy your set only from a dealer who will give you a return and/or
> exchange privilege if you are not happy or the set causes RFI to your
> station.
>
> Why do I say this? Mainly because of all of the variables that can exist
> between the store set-up and your particular installation. Yes, the sets
> that emit the most RF are most likely to be unusable in a ham's household.
> But ... even the "quiet" sets could be problems. Consider:
>
> 1. Where will you place the TV relative to your antennas? (The
> probability of coupling RFI into your radios from set-to-set is low. You
> are much more likely to couple into any antennas that are placed over or
> near the TV.)
>
> 2. How many interfaces will be connected to the TV? (TV antenna or
> cable/satellite box, game box, DVR, VCR [some of us still have and use
> them!], computer, stereo system, etc. The back panel of today's TV sets
is
> often one big jack field. I can't stand to see empty sockets, so I tend
to
> plug stuff into those sockets.)
>
> 3. Will the TV share any interfaces with equipment in your ham shack?
> (That would be a fine way to couple RFI into the ham gear without
involving
> an antenna.)
>
> All of the above are variables that can affect the end result of a given
> set in a given installation. For example, I am sitting in front of my 19"
> Toshiba LCD HDTV that I use as both a TV and as my computer monitor. It
is
> not in my shack, but I do have a 2m HT with me most of the time because I
> am trustee of the local 2m repeater. That machine is on 145.39 MHz
output.
> When I installed the TV set, all was well until I connected the VGA
monitor
> cable to it from the computer (which is a Dell desktop). I found that
with
> the TV OFF, I had birdies that would pop the squelch on the HT. As soon
as
> I switch the TV ON, all goes quiet and I have no interference to the HT.
> Go figure! I also have a DVD player and a stereo amplifier connected to
> the set. No problems with or without those units connected.
>
> Incidentally, the birdies on 145.39 MHz actually originate from my
Ethernet
> LAN. The HT is not affected unless I bring its antenna to within about 2
> feet of the unshielded Cat5E cable that carries the LAN. However, with
the
> TV off and the VGA cable connected to the rear jack of the TV, the birdies
> affect the HT to a distance of at least 3 feet. As soon as the set goes
> active, no problem.
>
> It is variables such as these why I suggest the "return option" when you
> buy a set. I feel that it is more practical than hauling equipment around
> when shopping. You can use the comments made on this list as a good way
to
> avoid the worst of the known noisy sets. Many have been mentioned during
> the past couple of years.
>
> 73, Dale
> WA9ENA
>
>
>
>
>
> > [Original Message]
> > From: W4PV <w4pv@comcast.net>
> > To: <rfi@contesting.com>
> > Date: 11/13/2010 11:35:32
> > Subject: [RFI] Plasma TV's
> >
> > Hello,
> >
> > I have read many e-mails extolling the RFI cleanness of LED televisions
> and how poor the shielding is on Plasma TV's. How can I determine if a
> perspective television produces RFI before I purchase it. Is their a
> device that a ham could afford that would sniff out a potential RFI
problem
> in one or more of the particular TV's of choice?
> >
> > Thank You,
> >
> > Patrick, W4PV
> > _______________________________________________
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> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
>
>
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