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Re: Topband: T-loaded vertical

To: <topband@contesting.com>
Subject: Re: Topband: T-loaded vertical
From: GEORGE WALLNER <aa7jv@atlanticbb.net>
Date: Wed, 19 Feb 2020 23:39:30 -0500
List-post: <mailto:topband@contesting.com>
The T has another advantage: it is better on 80 (and 40) if you can match it. A 160 m inverted L, with a substantial length horizontal wire, makes a poor 80 meter radiator because of high angles. A T will give you more low angle radiation.

73,
George,
AA7JV


On Wed, 19 Feb 2020 15:31:21 -0500
 "Ed Sawyer" <sawyered@earthlink.net> wrote:
Rick said it better.  Thanks Rick.  The T has been a great performer for me in 
4 different locations over the years.  I swear by it for 55 - 70 ft vertical 
sections.

Ed  N1UR

-----Original Message-----
From: Richard (Rick) Karlquist [mailto:richard@karlquist.com] Sent: Wednesday, February 19, 2020 3:04 PM
To: Ed Sawyer; donovanf@starpower.net; topband@contesting.com
Subject: Re: Topband: T-loaded vertical


On 2/19/2020 11:50 AM, Ed Sawyer wrote:
I have personally found that for Ts that are only 70 ft vertical, like mine, the 
ground losses of the long topped L are not as desirable as the cancelled out 
horizontal lobes of the T.  If the T were say 90 ft of vertical, I don’t think 
the T adds as much value.
Ed  N1UR


When you model an inverted L, the driving point resistance
goes up when you lengthen the top.  This it appears that
you decreased ground losses and your efficiency goes up.
However, if model vertical polarized radiation vs input
power, you find that your effective efficiency actually
goes down.

Extending the inverted L top out to where you have a 1/4
wavelength of wire seems very elegant.  The antenna
reaches resonance at 1830 and you get a low VSWR without
using a tuner.  If you model that vs a T vertical, there
is no comparison. The T wins.

Rick N6RK

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