O my GOSH!! Now I'm really concerned. I guess I better look into closing
down my station? For the past ten years I've been running about 360' of open
wire feeders to a 66' per side sloping dipole and running 1499 watts
(approximately....well...close!) into it with my Titan amp very actively
chasing DX and getting into every contest I can. What shocks me is I have no
high RF field in my basement, my own rabbit ear TV's and the neighbor's
about 75 feet away on each side of me have no TVI.
What have I been doing WRONG? Do you think it may have something to do with
making sure each side of my dipole is physically the exact same length and I
do NOT run the end of my antenna wire directly over my house? Or could it be
that the application of my smattering of amateur radio knowledge of
antenna/transmission line theory has something to do with it?
Tom/W4BQF
-----Original Message-----
From: AC5E@aol.com [mailto:AC5E@aol.com]
Sent: Thursday, October 17, 2002 10:52 AM
To: kb1ckt@yahoo.com
Cc: tentec@contesting.com
Subject: Re: [TenTec] Re: TWINCOM feedline?
How does a radiating feedline cause TVI? That depends on the individual
case, but...
In my case a radiating feedline about 20 feet from the local CATV system's
cable put enough energy into the CATV system to knock out the Playboy
channel
over most of our block. The local bunny fanciers were outraged, as were
the
late night porn movie fanciers.
I had coax running almost in contact with the CATV cable with no
interference
to any channel - but any attempt to use the open wire line resulted in nasty
telephone calls. While the SWR was well within 2:1 (a folded dipole
radiator
and 450 ohm wire) and was actually less at the band edges, efforts to
reduce
feedline radiation proved fruitless.
After some effort to get the CATV system to either replace their defective
cable, or at least step up their signal enough to override the leakage, I
gave it up. The same antenna with a choke balun followed by a 4:1 balun at
the feedpoint is completely TVI free.
73 Pete Allen AC5E
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