[RFI] 40M TVI problem

EP Swynar gswynar at durham.net
Mon Nov 13 15:35:45 EST 2006

Hi Serge,

There is a web site that is dedicated to the winding of common mode
suppressor chokes, for cases just as you describe...

What I got most out of reading it was simply that --- dependent upon the
offensive frequency --- the impedance offered to the unwanted RF intrusion
may not be enough with simply one choke. Have you tried winding two (or
more) in series, at both ends, to see if the increased impedance might be
just what you need to "...get it over the top"...?

It certainly soiunds like you're 90% there --- perhaps those extra chokes
may be all that you'll need at this point...

Good luck, & very

~73!~ Eddy VE3CUI - VE3XZ

----- Original Message -----
From: "SERGE BERTUZZO" <smbertuzzo at rogers.com>
To: <rfi at contesting.com>
Sent: Monday, November 13, 2006 12:12 PM
Subject: [RFI] 40M TVI problem

> Hello everyone. While I am new to this list I have been reading the posts
for quite some time. Lots of great information.
> I primarily only operate CW/digital modes on HF on 80-10 meters. I use a
TA33JR for 20-15-10 meters and an Alpha Delta antenna f(inverted vee
configuartion) for 80/40 meters.
> 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
> Any assistance/guidance would be greatly appreciated. Thank you all in
> Regards,
> Serge
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