[RFI] Horizonal Sweep Noise
Wed, 8 Jul 1998 08:04:34 -0700
I had this problem plaguing me just recently. In my case, the neighbor
had installed a WebTV internet device on top his TV, then connected
a phone line to it which was hung to the ceiling and strung down
the hall to the phone jack. Nice antenna, huh?
Needless to say, I was hearing his tv set 5x9, especially when
I turned the quad directly to his house 70 feet from mine. I
put core mix #77 on ALL leads coming from the tv set, i.e.,
the phone line, power cord, audio/visual cables to the WebTV
device and the tv cable line. I also put an AC line filter on
his tv and put a radio shack phone interference filter on the
This cured the problem 100% and all tv harmonic noise has been
eliminated from this neighbor. I do have another neighbor causing
similar interference but only occasionally...so I'm not willing to
invest any money in that one yet!
73 John K7FD
> From: WX5L <email@example.com>
> To: firstname.lastname@example.org
> Subject: [RFI] Horizonal Sweep Noise
> Date: Wednesday, July 08, 1998 3:37 AM
> Has anyone had success eliminating horizonal sweep noise from a
> screaming TV?
> Horizonal sweep at 15.75 khz is rich in harmonics and often couples with
> the A/C line or cable feed and actually backfeeds acting as an antenna.
> If you hear a raspy a/c note on the HF bands especially 20 meters and
> below every 15.7 khz apart that's whats going on.
> I put a hefty common-mode ferrite choke mixture #43 on the offending
> TV(neighbor) and noticed a slight decrease but not enough to amount to
> Does anyone have any other ideas other than asking my neighbor to but
> another TV.
> New Orleans, Louisiana
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