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Re: [TowerTalk] Verticals

To: "TowerTalk List" <>
Subject: Re: [TowerTalk] Verticals
From: "David Thompson" <>
Reply-to: David Thompson <>
Date: Thu, 28 Dec 2006 21:29:30 -0500
List-post: <>
There is talk of shunt fed towers but two types of feeding towers as
verticals have not been mentioned.

1.    The N4KG reverse feed ekevated radial system in a 1994 QST magazine.
N4KG is a noted low band Dxer and his article gave several examples.  I
tapped my crank up at the 22 foot level and found that it was sitting at
1877 on the MFJ 259.  Using 4 Spi-Ro short dipole haves as radials I seemed
to worj fairly well.  I used the ON4UN book to try and calculate top loading
with a W9PNE X beam at 71 feet,
a KT34XA at 76 feet , a 2 el Cushcraft 40 at 86 feet, and a 2 meter Isopole
attached to the top of the mast.  My calculation was somewhat below the
actual reading of the MFJ-259 but the beams are all isolated from the mast
so only the Isopole added significant electrical height.  The rub was the
tower is right next to the house and I urned on mt wife's clock radio and
got into almost all the electronics so I turned to other antennas.

2.    The second was presented the 1975 ARRL Convention by Ralph Robinson
WA3YEE.  He used isolators to make even short towers half wave verticals.
There is a complete book on his method which is much more complecated than
shunt feed but Ralph says you eliminate the need for radials.  Please don't
ask me to fully explain his method,,,just find a ham with a copy of the
booklet.  I do remember the W3 who was using a 50 foot tower on 80 and he
seemed to work the DX ahead of everyone else.

Dave K4JRB


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