[RFI] Plasma TVs make big interference

Jim Larsen JimLarsen2002 at alaska.net
Wed Jan 7 13:24:18 EST 2004

I found this to be very interesting and disturbing if true.

Jim Larsen, AL7FS
Anchorage, Alaska

 From KL7HF, Del Seay
   Note from Del:
                     Jim Talens is an ex-FCC employee from the
                     Commission's legal department.

----- Original Message -----
From: Jim Talens
To: jtalens at rcn.com
Sent: Wednesday, January 07, 2004 3:29 PM
Subject: [cwops] FW: [PVRC] Plasma TVs make big interference

While BPL interference at HF may be looming, another souce of hashy noise
from the broadcast band up through at least 14 MHz is already here!  It's
those new "plasma", flat screened TVs.  I took a small, pocket sized portable
radio with ear plug into Costco this past weekend and was mortified to hear 
what I did when I was anywhere close to one of these "new, advanced" TV sets.

Now read the comments of others, posted on a broadcast engineer's reflector:


   I have run into plasma TV monitor RFI a couple of times.  I do
two-way radio and RFI investigations for a large electric utility
and have found these monitor emissions not only in the AM
broadcast band, but all the way up to around 15 MHz, at distances
of up to nearly 500 feet from the house.

   On one occasion, while tracking a problem for a ham with RFI and
while traveling down a short side street, my Sprague interference
receiver and the truck's AM radio started making harsh raspy video
type buzzes while listening at 530 kHz.  I looked into a house at
the end of the street and saw a large rectangular HDTV hanging on
the wall.  Due to the brightness of the display, I figured it had
to be plasma. I noted that the buzz characteristics changed as the
scene changed.  Since it was quite a distance from the complaining
ham, I moved on and continued tracking his original problem.

   Bill Smith, mailto:WILLIAM.SMITH at us.ngrid.com

    My in-laws purchased a plasma monitor.  I like to listen to
radio at night when I go to bed, at a location that is 47 feet
from the display.  On both a Sony ICF-2010 and GE SuperRadio III,
that TV takes out many stations that I previously could hear.
Even 0.5 to 1 mv/m signals had traces of noise under them.
Weaker stations at less than 0.1 mv/m that were previously
audible, became completely inaudible.

   Fred Vobbe, WLIO radio


It's only going to get worse.


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