On 4/4/2012 2:16 AM, Rick - DJ0IP / NJ0IP wrote:
> I much prefer the telescoping fiberglass pole method. They go up and down
> in less than one minute. You can have a full size 40m vertical (33')
> without even having to guy it (if it is only temporary). Just have separate
> quarter wave wires for each band you want to operate.
I think I agree with Rick on this point. You could make
a simple vertical on one of those really light weight
and very flexible Spiderbeam type fiberglass poles,
supported by a simple base at the foot, and then roll
out some radials - as many as you can manage - depending
on your threshold for screwing around, but maybe 8
would be a good start - I would use like 16-20 even if they
were only 20 feet long, each. More shorter, is better
and fewer longer. But we each have a different threshold
for this sort of thing. But it would be a full quarter wave
vertical, and work swell. You could shorten it for any
higher band and use the same simple ground plane radials.
> NOW for low bands, Phil has put forth some outstanding suggestions for
> matching 43' verticals on 80 and 160. His suggestions here are some of the
> best I've ever seen.
While this is true, my correspondence with Phil over
the last couple of years leads me to think his matching
units are fairly substantial and bulky, not to mention
complex and expensive... probably not exactly suited
to quickie deployment for QRP in the field. Perhaps
you have seen something I have not... I am thinking of
the devices he shows on his web pages and in the articles
he published in QST last year or so.
>
> FINALLY, I started out in the early 1970's using home-brew mobile whips with
> coils in the middle. Once I switched to the long fishing poles (now days,
> there are much better purpose-made poles for ham radio), I never looked
> back. There is a huge difference.
>
> The old adage, make your wire higher and longer is still true (in general).
I think you could easily deploy one of the Spiderbeam type
fiberglass poles to make 1/4 wave verticals easily and
cheaply - with good results. I suspect they yield to the
wind before breaking, and snap back to straight with no
issues. A very simple base could be made - even if lashed
to a pipe or rod pounded into the ground a foot or so. Maybe
even stand in most winds without guys ropes.
I have used cheaper, less well made poles called Jackite poles
before, with excellent results (they are not as long or as
durable
I don't think) but they are easy to hold up from the base, and
they sway in the wind without issue or support. A better pole
which did not weigh substantially more would be ideal.
Heck... on 20 meters, I could easily set up a pair of them, or
one long one, on a push up mast, and make a quick-build
horizontal dipole that would be full sized, and which should
out perform any sort of Hamstick, BuddyPole, or other high Q
but shortened antenna. My experiments with this show such
antennas work well at relatively low or modest heights and
have way wider usable bandwidth than a high Q shortened
dipole design, such as the Hamstick or BuddyPole, etc.
I still favor the notion of a push up mast with simple two
wire dipoles - each acting as a guy support - terminating
at the far ends with an insulator, and rope to a ground stake
like a large, long tent stake, giving you two bands in an
Inverted V arrangement. Cheap, quick, light weight,
easy to deploy, and RESONANT. Similarly the
advantage of
the quarter wave vertical is that it is inherently resonant,
without a coupler- matchbox-tuner-transmatch, whatever
we call it, and even without adding a big coil inductor or
loading coil.
Even on 80 meters, I would prefer a large vertical wire,
with a loading coil - inductor, over a simple ground plane
over something like a screwdriver, or similar, high Q, but
extremely narrow bandwidth, radiator.
Just MY take.
========================= JHR =========================
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|