Lee,
It's been a while since I've read the Butternut manuals, but as I
recall, that coil is designed to act as a matching device, helping get
the impedance of the feedpoint to 50 ohms, or there about. At least on
the HF6V, from my experience, this wasn't necessary under the following
conditions:
1. If the only band used is 20 meters, since the stub used to feed the
antenna was an electrical 1/4 wave on 20.
2. If the antenna is mounted above ground, as a ground plane antenna.
Elevating the antenna seemed to change the feedpoint impedance. I ran
mine as a ground plane for years and had no issues of this sort, once I
removed the coil. When I used it mounted to ground, the coil did do its
work.
73 de N8AU, Jim in Raymore, MO
Date: Tue, 13 Dec 2005 13:02:15 -0800 (PST)
From: Lee Buller <k0wa@swbell.net>
Subject: [TowerTalk] Vertical Antenna Question
To: TowerTalk Reflector <towertalk@contesting.com>
Message-ID: <20051213210215.56953.qmail@web81308.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1
Liberal Arts Major type of question.....
On some vertical antennas (i.e. Butternut) there is a coil between the
feed point and ground. The coil is about 1 1/2" in diameter and about
10 to 12 turns. I think it is used for a DC ground return for
lightning. Then again....I may be wrong.
If I was to fabricate my own 1/4 wave vertical...is such a thing needed
for safety since my vertical I am planning does not have an actual
ground-ground...but a ground plane instead. I would say the antenna is
going to be a 1/4 wave ground plane.
Lee - K0WA
In our day and age it seems that Common Sense is in short supply. If
you don't have any Common Sense - get some and use it. If you can't
find any common sense, ask for help from somebody who has some common
sense.
------------------------------
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