Bob:
I built my shunt feed wire cage based on the design in Jeff Bigg's K1ZM
book "DXing on the Edge..." I bought it from the ARRL bookstore but you
might be able to find it on Amazon, etc. I used two widely-spaced wires
whereas he used three in a triangular form held off the side of his tower
with PVC pipe. I was surprised at how well it seems to work for me ( I
always get through and receive good reports.) Good luck.
73 de
Gene Smar AD3F
Bob and Gene,
Seasons Greetings
Over the years there have been a number of articles on using a cage to feed
a vertical antenna. Some of the ideas came from Laport's Antenna Engineering
book as well as in amateur radio magazines; DeMaw in QST in the early 70's
to name one.
I have been using the unipole design here in NH since 1979. I have a 12"
wire triangle 3' from the tower using 2x4"s as standoffs. Since this is
around a 200 ohm antenna, I use a step-up L network to feed the antenna.
Bottom line is it works.
Here are some references:
http://www.jmu.edu/wmra-eng/archive/mullaney-be.pdf
Oct 1975 QST page 25-26 by DeMaw (design I used)
>From Ham Radio Magazine
Shunt-fed tower (HN) N6HZ 74 Nov 79 +
Shunt-feed systems for grounded vertical radiators, how to design W4OQ
34 May 75 *many consider this article by John True a classic
Hope this helps
Craig
Craig Clark K1QX
PO Box 209
107 Fitzgerald Rd
Rindge NH 03461
(603) 899-6103 office
(603) 520 6577 cell
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