I have a tribander up about 55 ft. and about 95 ft. from the troublesome TV.
The phone company claims they have a filter at the entry to the house,
what the name of these different boxes are, I have no clue. Do know that
a cable runs from there to a box that one of the serviceman called a
coax converter. From there it seems there is a cat45 cable going to the
Internet modem and wireless router for the computers of the qth. Also
from there is another cable going to a splitter with cable that lead off
to the various tvs. At each of the tvs there are two boxes, again what
those are I don't know.
Also don't know if the ferrites are of the correct mix, just a bunch of
misc. ones I've acquired in the past. Some of them are the Radio Shack
clamp-ons.
thanks 73 Dwight NS9I
dgsvetan@rockwellcollins.com wrote:
> Dwight,
>
> An interesting problem, especially since I heard recently that some
> community CATV systems are planning to run digital video on CAT-5 lines
> around town. That's a truly scary thought. I have heard of one system in
> another town that is working, but they did use SHIELDED CAT-5E cable
> (verified by visual inspection by hams). In your case, a few questions
> come to mind:
>
> 1. What is the orientation of this one problem set relative to your
> antennas?
>
> 2. What is the connecting device between the TV and the phone lines? Is
> it a passive balun or an active device "converter" box?
>
> I saw K9YC's reply to your inquiry. Read and heed the info from his web
> site. The grounds you have are very nice and good for system protection
> from lightning damage, but this is strictly an RF overload problem
> somewhere. If the TV was good on an outside antenna before, it is
> probably not the set that is the problem now. You should concentrate your
> efforts on the interface between the TV and phone lines, and don't forget
> that if you use ferrites, be sure they are appropriate for the frequency
> bands you are using.
>
> Please keep us informed on your progress, and best luck.
>
> 73, Dale
> WA9ENA
>
>
>
>
>
> DGB <blueheron@Bayland.net>
> Sent by: rfi-bounces@contesting.com
> 03/31/2008 07:18 PM
>
> To
> rfi@contesting.com
> cc
>
> Subject
> [RFI] Digital TV Problems
>
>
>
>
>
>
> I've recently had subscribed to a service thru the fone lines that
> include TV and Internet. I've had the internet thru it for a long time.
>
> I have 4 tv's in the house hooked to this system.
>
> My shack is in a separate building but still about 30' from that problem
> tv. I've a good single point grounding system that is all connected to
> the tower, the service here in the shack, and the house's service. It's
> all connected undergnd with 2" copper and gnd rods every 16' (over 30
> rods).
>
> Recently I've been getting into the TV when xmtg but just one of the
> tv's. My signal scrambles the digital image, like tiling.
>
> I never had that problem when the tv had an outside antenna, even when
> running legal limit. I've put several clamps-ons on the problem tv. I
> also have a cat5 and telephone cable coming out here to the shak
> underground and have clamp-ons on them as well.
>
> Where do I start?
>
> Thanks ... 73 Dwight NS9I
>
>
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