[TowerTalk] Vertical Antenna Question

[Reicher, James]

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 at swbell.net>
Subject: [TowerTalk] Vertical Antenna Question
To: TowerTalk Reflector <towertalk at contesting.com>
Message-ID: <20051213210215.56953.qmail at 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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