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Where there is a will…
Often, one of the first problems one encounters when first
getting onto the HF bands is the antenna. It is now a simple matter to buy a
commercially manufactured transceiver, but the antenna still remains the biggest
challenge. At times it is the ability to even have an antenna, such in the case
of covenant and deed restrictions, or local town ordinances. But often it is
simply that newcomer lacks sufficient room to allow the installation of a decent
“skyhook”.
Such was my case nearly 5 years ago. I had purchased my
home before I was licensed, and as such did not anticipate the need for extra
land to accommodate an antenna. Nor, as it turns out, would my homeowners
association permit the installation of a tower. After some pondering, and being
resourceful, as we hams often are, I was able to use a large undeveloped tract
of land in back of my home to erect a 160-meter loop antenna. In part thanks to
the natural tree supports, I was able to secure over 500 feet of wire suspended
in the air, ready to send and receive RF.
How did work? Well if you read my article last year, you
know that it worked great! It was quiet on receive, as loops typically are, and
radiated strapping signal with very few RFI issues. You will notice that I use
the past tense in talking about my 160-meter loop, as it now no longer exists.
In the name of what goes as progress today, the developer
deceived it was time to cut down all of those nasty trees that once proudly held
my antenna, and turn the forest floor into a brown, muddy, soupy mess for all
the neighborhood to enjoy. Aside from my new eyesore, I faced a more critical
problem, critical at least for me as a ham. No antenna. No antenna equals no
fun. While I was away in Maine, the contractor clearing the land had cut the
wire for my antenna in half. My fault really for not removing it earlier.
So what does one do with 250 feet of wire on a piece of
property that measures perhaps 160 feet in depth, by 60 feet in width? I
pondered making a large loop antenna that would surround the perimeter, but
quickly dismissed the idea in light of the RFI, which would be experienced by my
own home, and my neighbors. The beauty of my former loop was that it was in back
of my house, and the RF radiated out into the woods not scrambling anyone’s TV
or phone, just warming a few chestnuts and squirrels.
I thought for a bit, and then it dawned up me. (I wish that
I would say it came to me as a blinding light and a flash of inspiration, but
that never seems to be my case. Instead it was only after downing a good part of
a pot of very black coffee one evening.) Sure my loop used to be horizontal, but
it would also work in the vertical plane, in fact it would radiate irrespective
of its orientation to the ground. The wire does not know or care which way it is
suspended; it just wants to get rid of the RF, caring not a bit which way it
sends it out. Hence the creation of what I fondly term as my “Zig-Zag” loop.
Imagine if you will, a loop antenna where three sides are
horizontal to the ground, but the fourth side is vertical. In fact, not just
vertical, but “zig-zagging” several times from the tops of the trees, to
about 7 feet from the ground. Using my trusty slingshot I was able to launch my
antenna support ropes into the trees perhaps 40 feet in the air. I then attached
the antenna wire to this rope, pulled it up to nearly its full height. The
dangling wire was then tied off about 7 feet from the ground, and the process
repeated again, resulting in a series of zigs and zags. This allowed me to fit
250 feet of wire into an area that really would have been hard pressed to allow
even a quarter of that. Each 40 foot vertical excursion ate up 40 feet of wire,
creating an antenna that was electrically a full wave loop on 75 meters, but
physically took up very little room.
How does it work you may ask? In one word, outstanding! I
was able to do my first formal check-in on the STARS Saturday morning net last
week, and the signal reports were excellent. Perhaps slight decreases from the
longer loop, but respectable never the less. As far as loading up with my
transmatch, no problem on 75, 40 or 20 meters. I have not tried the higher bands
yet, but I suspect the same results. And reception? It is very good, and quite,
nearly free of all of the RF hash emitted by the numerous light dimmers, TVs,
and other electric noisemakers in my neighborhood.
Is there a lesson in this? Not really, I just had some
extra time and owed Terry an article. Of course that is a lesson here, something
that we can all learn from. First, when you buy a home, consider the important
things, like how many trees there are for antenna supports, will the power
service handle that legal limit amp you just built up, and how much space is
there to install that beverage antenna you have been dreaming about for the last
10 years. Let the XYL be concerned about the other minor details like local
schools, exterior color and price, you need to concern yourself with the
important things! Those of us already in a home are often challenged in the
amount of space we have to erect our antennas. Do not let this discourage you.
Often we think we need to have large elaborate antenna arrays to enjoy the
hobby, and to radiate an effective signal. Nothing could be farther from the
truth. You can spend thousand of dollars on commercial antennas when a simple
spool of #18 wire will at times work just as well, if not better.
Like the solution to so many other problems, return to the
roots. Experiment! Whether you use my zigzag loop, a folded dipole, or other
form of shortened antenna, do not give up. Too often if a “textbook” antenna
cannot be erected, we give up the battle. The funny, and really delightful thing
about antennas is that there is no such thing as a textbook antenna. Each and
every QTH is different, and what works for your friend a few miles down the
road, may not work for you. Ground conductivities, houses, trees, and other RF
reflectors and absorbers all vary with location. Get out there, try and
experiment, you will be pleasantly surprised. After all, even the smallest wire
can radiate and receive, and something, no matter how small, is better than
nothing.
Where there is a will, there is a way!
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Amateur Radio Station W1UJR