360'! Even your RFI is dx!
-----Original Message-----
From: "Alderman, Chester" <CAlderma@ora.fda.gov>
To: "'tentec@contesting.com'" <tentec@contesting.com>
To: <tentec@contesting.com>
Date: Thu, 17 Oct 2002 11:24:34 -0400
Subject: RE: [TenTec] Re: TWINCOM feedline?
> 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
>
>
>
>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
|