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Re: Topband: 160 Antenna

To: Gary Kohtala - K7EK <gary.k7ek@yahoo.com>, topband@contesting.com, K4SAV <RadioXX@charter.net>
Subject: Re: Topband: 160 Antenna
From: "Richard (Rick) Karlquist" <richard@karlquist.com>
Date: Mon, 17 Dec 2018 09:36:45 -0800
List-post: <mailto:topband@contesting.com>


On 12/17/2018 9:10 AM, Gary Kohtala - K7EK via Topband wrote:
Short the braid and center conductor and attach that to your tuner single wire connection.. It will work much better than connecting only one side. This willgive you a top loaded vertical or semi vertical. I've done it with100w without issues of RFI. Higher power might be a different story,depending on the physical placement of things in and around your shack.Having a decent ground
If you feed a dipole with a balanced line, then
shorting it together at the bottom properly
turns the antenna into a T top vertical.

If you feed a dipole with coax possibly including
a balun, the scheme you describe doesn't really
work like the balanced line system.  Shorting
the braid and center conductor at the bottom
is only really effective if the electrical
length of the coax is a multiple of a half
wavelength, and only if there is no balun
at the feedpoint.  If the coax is an odd
multiple of a quarter wave, then the short
at the bottom does nothing.  The leg connected
the center conductor will not be driven.  There
are so many random variables that any given antenna
might sort of work by chance.

73
Rick N6RK
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