I can vouch for the spud gun built by the California ham. At age 72, my
ability
to use a slingshot or compound bow and hit anything is gone, gone, gone. I
have
A lot of 80 ft pines, and really wanted to put some wire antennas. A buddy
of mine
suggested I build one of the spud guns, but after reading about them decided
to buy
one. Order and ship time was over 10 weeks, but it was worth waiting form.
Biggest problem was calibrating height of shot to amount of air pressure,
but once
I figured that out, I can not put a weighted tennis ball just about anywhere
i
want to. And the bright yellow tennis balls are easy to find once you shoot
them.
Works great! I now have a 400 ft delta loop with the top (base) of 200 ft
of wire up
at the 80 ft level. Best antenna for 80 and 40 meters I've ever owned. If
the
KW Johnson Matchbox worked on 160 I'm sure the antenna would too.
Dave WN5V
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Jim Brown K9YC
Sent: Monday, July 26, 2010 12:44 PM
To: TEN TEC DISCUSSION
Subject: Re: [TenTec] Hanging antennas Off topic
On Mon, 26 Jul 2010 00:20:11 -0400, John Molenda wrote:
>spud gun with potatoes and tennis balls
Over most of my ham career, most of my antennas have been hung in trees.
Here in CA, they're up 120 ft in redwoods. I've tried a lot of things. The
best, by far, is the pneumatic tennis ball launcher built by a ham near San
Francisco. www.antennalaunchers.com Several of my friends one them. One
of them, K2RD, came over to help me get my first antenna up at that level.
With his first shot, he cleared the top of my tallest redwood (about 170
ft) by at least 10 ft.
I also own an industrial grade slingshot sold by Sherrill Tree Service (in
NC). http://sherrilltree.com It's good for 80-100 ft, costs about $160
with line and weights. It takes two men and a boy to hit max heights. The
club I belonged to in Chicago owns one that we used quite effectively to
launch Field Day antennas, and loaned to members for their own antennas.
Some of the guys out here like the EZHang that's advertised in QST. And
there are guys who tie a small gauge rope to a pop bottle filled with
water, get it going with a circling action, and launch it over a tree. I've
watched guys get up 50 ft or so.
ALL of these methods take skill, a learning curve, and PATIENCE. You WILL
get tangled, you WILL lose wieghts, you WILL lose some line, and you WILL
need to make multiple tries at hitting the sweet spot. It typically takes
at least several hours to get a wire antenna up where you really want it,
and can often take longer. And it is MUCH easier with help. I like to have
at least three guys (including me) on any wire antenna launching team. But
if you persevere, you'll have a better signal, and the result will be worth
it.
There are a lot more ideas, including antenna construction techniques,
parts recommendations and sources, and antenna concepts in two different
articles on my website.
http://audiosystemsgroup.com/LimitedSpaceAntennasPPT.pdf
http://audiosystemsgroup.com/LimitedSpaceAntennas.pdf
73, Jim Brown K9YC
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