[RFI] Sony TV Noise Generator

EDWARDS, EDDIE J eedwards@oppd.com
Mon, 21 Oct 2002 08:54:01 -0500

My advice: SELL IT!  If it's new, take it back.  And try a Panasonic.
My moderately priced (~$300) Panasonic is clean as a whistle and doesn't
even pick up RFI.  I only have an AC surge suppressor on my Panasonic.

I had a similar Sony trinitron XBR model that put out a tremendous
broadband signal.  Only difference was mine at least stopped when turned
off.  I never was able to eliminate the noise even after $100+ worth of
external and internal filtering.  I was even allowed to talk on the
phone about it with a Sony engineer who was a ham.  I was only able to
clean up the incoming RFI (audio rectification) using internal ferrites.

You expect more from a $750 set.  The power supply is a switcher with
very poor EMI design (that's the Sony engr's words!), and eventually it
was the death of my set when the PS died.  The closer it got to failing,
the stronger the PS noise got.

Sorry I can't be of more help, but a bad design to begin with leaves
little room for improvement.  Since yours is ON all the time, I'd guess
it's either the switching PS or the Remote Control circuitry.  Either
way, it'll be a bear to eliminate, if it even can be at all.  Try moving
the antenna farther and farther away from the set to see what happens.
You might be able to get far enough away to attenuate the noise,
assuming you have the AC filtered so it's not being re-radiated by the
houses AC wiring.

 de ed 

-----Original Message-----
From: Bob Farkaly

While waiting patiently for my upcoming battle with the City of Poway,
CA (Poway does not recognize PRB-1), I put up a sloping "J" antenna for
20 meters. It works better than I would have expected. Anyway, listening
on 20 meters shows a noise level at S9+10. Sounded like constant AC line
noise. First, checked outside (for about 5 minutes) without finding a
possible source. Checking the in-house circuits, I found the Sony
KV-35V68 television in the family room to be the culprit. 

The noise is there with the television power switch off or on. The act
of unplugging the appliance reduces the 20 meter band noise level from
S9+10 (which I cannot live with) to S2 (which I can live with).

I have tried a Radio Shack AC power line filter, but it had zero effect.

Searching the Web (with Google) gave me no help. 

Any advice on how to tame a Sony TV would be welcome. 

Bob Farkaly, K9RHY
Poway, CA 92064