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Re: Topband: New Antenna

To: topband@contesting.com
Subject: Re: Topband: New Antenna
From: "Donald Chester" <k4kyv@hotmail.com>
Date: Mon, 27 Dec 2004 20:40:15 +0000
List-post: <mailto:topband@contesting.com>

This may run counter to other suggestions you will receive, but here goes.
Use the flag pole to support the vertical leg of an inverted L, and the
tower
to support the far end.  This will give the inv L an upward slope, so that
all of the antenna is working for you.

If you use the tower as the vertical support and slope the wire down to the
flag pole, there will be a modest cancellation of radiation from the top-
most part of the vertical section. If effect, it will be as if the vertical
section
was about the same height as the flag pole.


If you use any vertical configuration, consider what you will do for ground
radials.
A reasonably symmetrical layout may dictate one support or the other as the
center of the antenna system.

Better still, electrically bond the horizontal wire to the top of the flag pole using a brass clamp, and shunt feed the flag pole, letting it serve as the actual vertical radiator. Lay out a radial ground system around the pole.


If it is physically impossible to get to the top of the pole to attach the wire, maybe a better solution would be to attach a vertical whip made of metal tubing to the top of the tower and shunt feed the tower as a shortened vertical antenna. Of course, the radial system would go around the tower in that case, and any guy wires would need to be insulated from the tower, and preferably broken up with strain insulators.



Don K4KYV


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