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Re: Topband: Inverted L improvements - Part 3 (now with data)

To: <topband@contesting.com>
Subject: Re: Topband: Inverted L improvements - Part 3 (now with data)
From: GEORGE WALLNER <aa7jv@atlanticbb.net>
Date: Tue, 22 Jan 2019 10:52:11 -0500
List-post: <mailto:topband@contesting.com>
Todd,
The resistive component should be going down with more radials, not up.
Maybe you are not measuring it the right way, or something in the radial system could be resonant (which may be a good thing).

Normally, with these antennas, lower R is better (less loss).

I have just measured a top loaded 57 foot tall vertical that stands in salt-water, which is an almost perfect ground. The feed point R is 8.5 Ohms. (Using an AIM-55 analyzer.)

Anyway, does your antenna get out? That is the ultimate test.

George,
AA7JV/C6AGU


On Mon, 21 Jan 2019 17:45:52 -0800
 Todd Goins <tgoins@gmail.com> wrote:
Hello,

Per many people's recommendations I added 800ft of radials today. That is 8
x 100ft each.  It made a difference on the analyzer which I'll summarize
below. It was dark when I finished but here are a few data points. I think
it is better. The wide SWR curve still bothers me but the resistance is
coming up.

This is also using the new K9YC cookbook choke with 18 turns of RG400
around a 2.4" type 31 toroid.

The values are Freq, SWR, R, X, Z

1810  1.43  42.0  -14.5  44.5
1820  1.31  43.2  -10.7  44.5
1830  1.21  44.1  -6.7   44.7
1840  1.13  45.0  -2.5   45.1
1850  1.10  45.9  1.7   45.9
1860  1.14  47.0  5.7  47.3
1870  1.23  48.0  10.1  49.1
1880  1.34  49.1  14.7  51.2

Any thoughts?  The 160 CW contest is only 4 days away, I don't have a lot
more time to make changes but I could run a "few" more radials...

73,
Todd - NR7RR
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