[TenTec] TWINCOM feedline ?????????????

Gary Hoffman Gary Hoffman" <ghoffman@spacetech.com
Tue, 15 Oct 2002 20:09:08 -0400

Why would a wider spaced feed line radiate more ?  It should not
radiate at all, unless you are assuming there is unbalance, or poor
construction.  But, given proper implementation, it should radiate nothing.

73 de Gary, AA2IZ

----- Original Message ----- 
From: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
To: "Rob Atkinson, K5UJ" <k5uj@hotmail.com>
Cc: <tentec@contesting.com>
Sent: Tuesday, October 15, 2002 1:54 PM
Subject: Re: [TenTec] TWINCOM feedline ?????????????

> The wider the space the more the feed line radiates. The thin spacers of
> the TWINWIRE compared to the plastic ladder lines means its less
> affected by wind, and maybe by ice. I've used flat lines for decades but
> found when hanging 50 or 60 feet from the antenna to the ground anchor
> (I try to keep them under tension) that they have too effective an
> airfoil and a bit of normal Iowa wind will break them. I've used 1"
> spaced #18 copperweld with plastic spacers more recently with better
> results except when there's a breeze and its coated with ice it breaks
> into several pieces.
> There is no advantage to 700 ohms over 450 or 600 ohms, but there is
> advantage at the tuner end for any of those impedances over coax when
> the antenna is a full wave long and the feed line is an odd multiple of
> a quarter wave long.
> 73, Jerry, K0CQ
> -- 
> Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
> Reproduction by permission only.
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