David knows what he is talking about. Also try to narrow down. Remove
DVD, Cable box, etc. to see if problem goes away. You can feed the cable
line directly into the TV and check out the analog cable channels for RFI.
My limited experience usually is that the attached boxes (VCR, DVD) are
receiving the signal and feeding it into the TV. If you see it just with
the TV and cable line connected then you have problems. If it goes away,
you have less connections/equipment to worry about.
From: firstname.lastname@example.org [mailto:email@example.com] On
Behalf Of David Robbins K1TTT
Sent: Saturday, January 26, 2008 11:14 AM
Subject: Re: [RFI] TV RFI
If you have cable tv and have tvi your problem will not be solved with high
pass filters or low pass filters. Your problems is most likely one of:
1. VERY poor grounding resulting in extremely high currents in house power
conductors... this is the ONLY one that you might be able to fix by doing
something to the radio and grounding system.
2. The antenna is WAY too close to the house, nothing to do here but put up
a higher tower or learn to like qrp.
3. The TV has a pin-1 or shielding problem... that is, it's the tv's fault
that it is letting rf in through the power cord or directly through the
case. Try a power line filter, and also torroids on all the cables between
the tv/cable/dvd/etc, if that doesn't work buy a new tv or wrap it in
aluminum foil like mine is.
4. The cable system is leaky... either due to poor connections on the road
end, or bad installations in the house. Take off all the taps, splitters,
extra boxes, dvd players, surround sound, etc. check the crimp connectors
to be sure their grounds are really connected, then try it with just one tv
direct to the cable... if you still have problems get the cable company to
check their connectors and grounds outside.
David Robbins K1TTT
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: firstname.lastname@example.org [mailto:email@example.com]
> On Behalf Of firstname.lastname@example.org
> Sent: Saturday, January 26, 2008 19:09
> To: email@example.com
> Subject: [RFI] TV RFI
> I am sure this topic has come up a lot, but I would like to put a
> different spin on it.
> What brand / type are you using?
> Does it work (does your XYL or neighbors like the results)?
> Would you recommend it to a fellow Ham?
> Did you make your own?
> Would you share how you built it with the list?
> The reason for all these questions? I have TVI. I have to get rid of
> it or not use the amp I bought. I get a little TVI with out the amp
> and major TVI with it.
> I have cable tv. I have my radio equipment grounded to a single pc of
> copper pipe about 12 " long up under the desk, then an 8 gauge wire
> from the pipe to an 8' and a 4' ground rods.
> I will be buying High Pass Filters this coming week. I have 4 good
> neighbors that I like and want to be a good Ham to them. I bought the
> amp to use not to look at. Thanks.
> Rod kc7vqr
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