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Re: Topband: Top Hat Vertical

To: topband@contesting.com
Subject: Re: Topband: Top Hat Vertical
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Wed, 1 Jul 2015 08:39:50 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Hi Ed,

The height of my Tee vertical was determined by the rigging points in trees to support the ends, with the design guideline that higher is better. :) The length of the top was then determined by what it took to get that 50 ohm match.

73, Jim K9YC

On Wed,7/1/2015 2:35 AM, Ed Sawyer wrote:
“Same here. My T vertical for 160 is 100 ft vertical and 82 ft horizontal.
That makes the antenna resonant below the band, with a feedpoint Z of 50
ohms plus some inductive reactance on 160M. I add series C to tune out the
L. The same idea will certainly work on 80M.”

I believe that this antenna is functioning as a 3/8 wave vertical.  Which is
nice, but not necessary for good performance.

I have a 70 ft high vertical portion with a total hat of about 45 ft (22.5
ft x 2).  It resonates at 1.84Mhz with 20 Ohm impedance.  It is fed against
a ground rod and 45 radials – mostly ¼ long.

Works quite well.

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