From: "SERGE BERTUZZO" <smbertuzzo@rogers.com>
> To: <rfi@contesting.com>
> Sent: Monday, November 13, 2006 12:12 PM
> I subscribe to a satelliet TV service. I notice
> interference on 40M when I
> operate with >40 watts. I have no interference on any of
> the other bands
> including 80M. On 40 M, I have used chokes on all
> input/outputs to the
> receiver as well as on the main cable feed from the
> satellite dish. I found
> that by putting (2 chokes - one near the receiver and one
> right at the cable
> outlet to the room) That I was able to eliminate most of
> the interference.
> My problem is that I seem to be unable to remove the last
> remaind bit of
> herring bone TVI when I operate on 40 Meters. I also have
> a choke on the
> output from the satellite receiver to the television set.
> If I reduce power
> to 20-25 watts I am able to eliminate the last bit of
> herring bone
> interference.
Serge,
I have corrected many dozens of TV systems near high power
transmitters. One of them was within a few hundred feet of a
large AM broadcast station. You could get burns and draw
sparks from the coaxial cables feeding the TV sets.
The single most effective thing that reduced interference
was connecting the cable shield to the power line safety
ground at the outlet feeding the TV sets. That single thing
was more effective than any other combination of things. My
own system in my house has that same method. Not a common
mode choke on anything.
At every TV system in my house, I have a outlet strip
designed to prevent lightning damage. Those boxes ground the
center safety pin of the power line to the cable connectors
on the box. In addition, I have added two .01 250VAC (1.4kV
dc) UL/CSA rated line bypass capacitors inside the box. One
from the outlet neutral to safety ground, the other
capacitor across the line.
I don't have RFI, I don't have lighting damage.
73 Tom
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