[RFI] RFI from Horizonal Sweep

Bob Tellefsen n6wg at earthlink.net
Wed Jan 7 09:59:51 EST 2004

Have you done anything with the ac power cord?
RFI can also emerge and be radiated by the power
cord.  Putting ferrites on it is a good place to start.
73, Bob N6WG

-----Original Message-----
From: rfi-bounces at contesting.com [mailto:rfi-bounces at contesting.com]On
Behalf Of WX5L
Sent: Tuesday, January 06, 2004 6:05 PM
To: RFI at contesting.com
Subject: [RFI] RFI from Horizonal Sweep


Has anyone had success eliminating the RFI caused by the 15.75 khz horizonal
sweep from televisions. These signals are heard as rough-ac notes every
15.75 khz. These harmonic signals carry well into the HF bands and actually
change in tone slightly as the picture changes on the screen. Unfortunately,
some of this energy gets coupled and is backfed into the cable drop and act
as a pretty good antenna. I would think too some radiates directly from
unshielded wiring in the sweep circuit. I guess we can attribute that to the
cost cutting measures taken to keep TV's cheap. We all suffer because of
that either with RFI ingress or RFI egress.

I have tried #77 toriods at the cable input of the TV with slight success
but still much remains.

Building a faraday cage around the set is not an option as it's a large
widescreen set.

Anyone have any success?


WX5L at charter.net
Thibodaux, Louisiana

RFI mailing list
RFI at contesting.com

More information about the RFI mailing list