[RFI] RFI from Horizonal Sweep

WX5L wx5l at charter.net
Tue Jan 6 20:05:07 EST 2004


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

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