Yes, that's also a very good antenna, James.
Just be sure you keep it real lightweight, or your fiberglass pole will bend
too much.
It's no problem to build lightweight dipoles, but DO NOT USE the 60 year old
examples the ARRL still shows in their antenna books. Use lightweight
stuff. Plexiglass insulators, heavy duty fishing line or twine for rope,
etc.
The only thing I would do different to what James described is, instead of
using a pipe for the base mount, I would use a piece of angle iron.
Why?
First, it weighs less.
Second, you can strap the retracted mast to the angle iron using two small
straps (camping supplies).
That way the mast is fixed and you don't have to hold it while telescoping
the fiberglass pole segments up.
Here's a picture of my installation at home using this method:
http://www.dj0ip.de/antennas/spiderbeam/pole-base-mount/
(that's a heavy duty angle iron, because it's supporting an 18m pole).
If you use a smaller pipe than the ID of the fiberglass pole, you have to
extend the pole before you can slide it over the pipe. This can be
inconvenient when you are working alone. With a helper, no problem.
With a large pipe, you can slide the pole inside of it and don't have to
hold the pole either, but a large pipe is very heavy.
In practice, 9 times out of ten you will find something to use, like a fence
post or small tree, and you don't have to use anything. I usually just
strapped it to my motorbike, but most people probably aren't traveling by
bike.
ANOTHER thing is to take a very small pipe (1" od) and very short (abt. 1
ft.) and then pound it into the ground under your car's rear view mirror.
Put a cap on the short piece of pipe before pounding it into the ground.
Lift the retracted pole and set it over the pipe (pipe sticking about 4 or 5
inches out of the ground, and strap the pole to the rear view mirror (or tie
it with rope). Then you can push it up, one section at a time, all by
yourself.
GUYING THE POLE:
Buy a cheap flimsy pole and worry about guying.
- Or -
Buy a good quality pole, hang a lightweight wire antenna on it and don't
even worry about guying.
It's not necessary.
This is not theory guys, I've been doing this for over 30 years.
Back in the days when I used cheap fishing poles (crappie poles), I broke a
lot of poles.
I have never broken one of the poles like the ones Scott sells and I use
these all the time.
73
Rick, DJ0IP
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Richards
Sent: Wednesday, March 28, 2012 5:22 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Using an Argosy in the Field
My favorite plan for a portable field antenna is...
Push up sections of fiberglass mast. At the top, you
have a feed point for two opposing dipoles - each
element of which is set 90 degrees from the next,
adjacent elements, respectively. Measure these
for the two bands you want to work most... and add
sufficient rope to the end so the construct is both
antenna and guy line. Stake the lines with camping
tent stakes.
Pound a short piece of water pipe (which is just
larger in inside diameter than the mast) into the
ground as a base that keeps the bottom of the
mast from moving about. It does not have to be
deep, just deep enough to keep the mast from
squiggling about - you can pull it up easily when
you move on. Another solution when using
hollow masts, is to pound a short rod or pipe
which has an outside diameter less then the
inside diameter of the mast tubing, and that
will keep it from sliding about. A little electrical
or duct tape will serve to minimize abrasion.
The four elements of the dipoles serve as radiators
and guy lines, and if it is not really windy, this
is sufficient to hold the whole thing together.
Otherwise a second set of guy lines can be used,
maybe just 3 more, if you mast is rally tall and
it gets a bit windy out.
A telescoping mast with its own quick release
fasteners often folds down to a single 36-48 inch
item for traveling. Roll up the wire elements
separately, pick up your base rod or pipe, and
move out when HQ gives the order to bug out.
I have friends using this design for monthly QRP field days during the
summer months. This will be a full sized dipole, and way more efficient
than a BuddyPole, also probably twice as high in the air.
======================= K8JHR ==========================
On 3/27/2012 3:02 PM, John wrote:
> What are good choices for portable antennas? I guess I would start
> with a buddy-pole or similar antenna and go from there.
=======================================================
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