OK, Rick, I get all that. It -IS - a difficult choice and not as
clear cut as one might, at first blush, think.
As I mentioned in another post, I am contemplating making either a 20 m
vertical dipole or a 20 m vertical quarter wave with tuned elevated
radials. I purchased some aluminum tubing to make a rotatable dipole,
but I think I selected so small diameter tubing as it sorta sags and
flops in the wind if I jiggle it. I made both 6 meter and a 10 meter
dipoles from similar sized aluminum tubing, and they seem quite study
and weather resistant. Should eve hold a couple birds who might perch
thereupon. But I think I need larger, stiffer elements to go for a 20
meter design.
I am closely tuned into your comments on the logistics of raising a full
sized half-wave vertical dipole, but on 20 meters this would need a
minimum of 20-25 feet and that can be done with wooden masts, metal
masts, or even make the antenna its own mast as a stand-alone item
(one could use a fiberglass rod for the first X feet, and then run the
lower element to another, short fiberglass rod (center insulator) and
then run the higher, second element up higher. Guy the whole thing at
approx 40 foot total height. But, a 20 foot high center mounting point
is doable even with a home brew wooden mast (a friend of mine made a
mast out of coupled /doubled-up two-by-fours to hold the end of a sloper
from his tower... and I could copy that.)
But a quarter wave ground plane employing three or four approx 17 foot
radials mounted on a 15-20 foot mast on my back deck would be even
easier to make, erect, and deploy. Unfortunately, I think the tubing
have now is still too wobbly, wiggly and flexible to take the sometimes
high winds we get off Lake Michigan here in West Mich. But, I persist
with the notion because I hate to waste the tubing I purchased and have
not figured out another good use for it !
So... ALL of this discussion, from you and all the others guys, has been
of particular interest to me both academically and practically as I play
ham radio and design new antennas to erect.
So, until I figure a use for this tubing.... I will probably hang the
new OCF dipole I have built, together with one or the 6 or 10 meter
aluminum dipoles, and see how they work. I am just a bit frustrated
because the prospect of a nicely tuned, balanced and adjusted 20 dipole
or ground plane appeals to me - as my other HF antenna is an untuned,
unbalanced 43 foot aluminum monopole - which works swell, but not, I
figure, as well as a dedicated 20 meter ground plane or vertical dipole
would work on 20 m. I don't quite know what I would do with all the
greater efficiency I might have !
So, thanks for the answer. Very helpful, even if not decisive !
I would love to have all you guys over for a big luncheon, with plenty
of beer and other libations of choice, as an antenna think tank to
debate what I might actually do. We might not reach a consensus, but
I am at present suffering analysis paralysis.
===================== James -K8JHR =====================
On 1/6/2011 4:16 PM, Rick - NJ0IP / DJ0IP wrote:
James, that is a tough call because it is not really apples to apples.
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