I totally concur with Ron. In many cases, sloppy installed F connectors on
TV coax lines and interconnect cables contributes to some degree of
radiation. Additionally, filtering on the AC line at the TV, using donut
torroids or the clamp on torroids will cure the concerns. As to the use of
"surge protectors, noise filter AC strips", I don't put much value in them.
They still leave the power cord with some ability to radiate and thus
unprotected. As to surge protection, the best surge protection is
accomplished by installing or having installed a "secondary surge arrestor"
at your main breaker panel. These are available from your power company for
a monthly fee or from your local electrical supplier for some $30 or so.
Usually RFI into sound systems is the result of RF induced into the speaker
lines and being rectified by the junction in the output device of the amp.
Again a donut or clamp on torroid devices installed with 5 to 7 turns of
speaker line and mounted close as practical to the amp is the cure. I do
not advocate hanging a bunch of C's across the lines as this can effect amp
electrical stability or audio response.
As to HDTV, yes I'm a believer. Simply outstanding picture quality. And
you might as well prepare for what's coming and get ready. In the very near
future all analog TV transmitters will be turned off. If you don't have one
of the new HD TV's then you may end up having to get a down converter from
your cable company or satellite provider.
In my operation, no TVI even at legal limit HF power, and having the TV
antenna side mounted on the tower that supports the ham antennas. All TV
stations are some 65 miles or more distance. No TVI what so ever! Good
clean installation and good coax makes for success.
73
Bob, K4TAX
----- Original Message -----
From: "Ron Castro" <ronc@sonic.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Tuesday, November 20, 2007 10:47 AM
Subject: Re: [TenTec] OT: RFI from Plasma TV?
Bernie, I keep hearing about all the awful RFI from plasmas, but I have a
50" Pioneer plasma that's no more than 25' from the base of the tower and
have never had even the mildest RFI from it. Not only that, but at full
power, there is no interference to the plasma from the radios on any band.
The Onkyo 5.1 Surround Sound system that I added after I got the set got
really bad RFI from 20 meters, but some torroids on each of the speak
leads,
the power cord (including the separate cord on the sub-woofer) and cable
connection cleared it up 100%.
BTW, if you haven't experienced HDTV on a good plasma screen with Surround
Sound and with good quality 1080i source material (Discovery Channel HD,
National Geo HD, etc.) you're in for a real treat...you'll never go back
to
analog!
Ron N6IE
www.N6IE.com
----- Original Message -----
From: <K5XS@aol.com>
To: <tentec@contesting.com>
Sent: Tuesday, November 20, 2007 8:28 AM
Subject: [TenTec] OT: RFI from Plasma TV?
My XYL is tired of my fixing our 25+ year-old Sony television. I note
there
are some attractive prices on plasma TVs for "Black Friday."
Does anyone know if the reports I've heard about serious plasma TV RFI
problems are true? Will my Orion II be suffering while the family is
watching?
Thanks for any thoughts.
Happy Thanksgiving, everyone.
Bernie
K5XS
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