[TenTec] OT: RFI from Plasma TV?

[Rick Williams]

Bernie I own a Panasonic 50 inch plasma and the short answer is yes.  Just
yesterday I received the message below from Panasonic (Canada).  I have
already installed a large torroid on the power cord (the stock cord IS
shielded with a built it torroid and my added torroid with 8-turns of the
power cord seemed to do nothing), an excellent surge protector (that seemed
to make things worse), put the TV on another circuit and the rest of course
is chaff thrown up by the manufacturer (the GND system meets current codes
and the plug is wired correctly).  The change of circuit DID help somewhat.
The noise introduced by the TV on certain frequencies on the 80 metre band
is approximately 2 S-units (i.e. significant) and similar on selected
frequencies on 20 and other bands.  So it's all over the place on all the
bands I work with all the antennas I use.

I put every split choke I own on the power line along with the large wound
torroid with no change.

The TV has a built-in EMI filter at the plug (I can see it through the vent
holes) so placing an additional Corcom filter in series seemed to make
things worse.  Finally, I have a large isolation transformer, currently
serving as a doorstop in the shack, that will be installed later to see if
it helps.

>From the Panasonic note they seem convinced that the power cord is
radiating.  My fear is that the plasma design itself is the source of the
interference and that will be significantly more difficult, if not
impossible, to resolve.

73, 

Rick 
VE7TK

Website:  http://www3.telus.net/ve7tk  



-----Original Message-----
From: IMS...Viera_Concierge  
Sent: Monday, November 19, 2007 14:22
Subject: RE: Technical Support, Television - VIERA LCD/Plasma

Thank you for contacting Panasonic Canada Inc.  Please be advised that in
order for our TVs to be sold legally in Canada they have to be certified and
approved by the FCC as well as Communications Canada for the amount of
interference allowed from the set.  If our TVs did not meet these standards
we would not be allowed to sell them.  Normally any type of interference is
related to the other equipment, and not with the TV itself.

Here are a few troubleshooting tips that our technical staff asked us to
pass along to you:

1.	You can purchase a noise choke/heavy-duty ferrite core to attach to
the power cord.  This type of item can be purchased at your local Future
Shop, Best Buy, The Source by Circuit City, etc.

2.	You can purchase a superior quality surge protector/power bar that
has noise or line conditioning (filtering).

3.	If possible, plug your TV into a different circuit.

4.	Ensure the grounding in the house is in proper working condition.

5.	Test the AC plug that the TV is connected or that your power
bar/surge protector is connected to make sure it tests OK.


We hope you find the above information helpful.

Sincerely,
Panasonic Canada Inc.
Viera Support Team

bg 


------------

Subject: 	[TenTec] OT: RFI from Plasma TV?
Date: 	Tue, 20 Nov 2007 11:28:32 EST

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