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Old August 25th 05, 05:44 AM
Roy Lewallen
 
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Jerry wrote:

Roy,
I built basically a loaded mobile antenna that went onto an airport
building in Raleigh, NC (about 60 feet) I was reluctant to build it because
I was afraid the people that I made it for (CAP) might not know how to do
the elevated radials. I was afraid they might come back on me. I reckon I am
one of those "trial and error" hams that has tried about everything in the
last 40 years and I am still learning. Anyhoo, BOY was I WRONG! They put
the thing on the air and it really puts out a good signal! None of us have
done any measurements or NEC modeling, etc. Frankly, I was surprised as I
had done very few vertical installations (well, I've got an AV8 vertical
all-bander). All I know is, at the 60-70 foot level with tuned radials, it
really sings!

73

Jerry
K4KWH


I spend a lot of time learning about how antennas work, and try to pass
the information along as best I can. But I find over and over again that
most people don't have the ability to evaluate things in anything but a
binary fashion -- everything has to be "good" or "bad" (or "good" and
"evil"), "theory" or "experiment", "perfect" or "no good"; antennas
either "work" or "don't work". So what I say is often interpreted as a
statement that an antenna has to be perfect in order to work well, or to
"work" at all -- whatever that means. But that's not at all what I'm
saying. Let me try once again to clarify what I mean.

Just about anything will radiate, from a dummy load on up. But some
antennas radiate a greater fraction of the applied power than others,
and some radiate more in desired directions than others. What I try to
do is to understand how they work so I can, if I want, optimize an
antenna for a particular purpose. (And I don't necessarily always want
to -- sometimes it's not worth the trouble.) But an antenna doesn't have
to be optimum in order to talk to people. It doesn't even have to be
optimum to get sixty-over-nine reports and break pileups. And it doesn't
even have to be anywhere near optimum in order to provide you with many
pleasant QSOs. You don't have to understand anything at all about how
antennas work to put one up that will give you many hours of fine QSOs
-- I must have put up hundreds without having a clue about how they
really worked, and I worked plenty of stations. And I, like anyone else
who's been around a few years, have a handful of great stories about
some really crappy antenna that worked the rare DX. (I've even done it
with a crappy antenna and QRP.) What you have to understand is that you
can work *more* stations, more reliably, if you do take the time and
trouble (and if your yard and pocketbook will allow) to make your
antenna more efficient and make it concentrate its radiation in the
directions you want. But to a lot of people, it's not worth the time and
trouble -- and that's fine.

Some people simply aren't interested in the technical aspects of the
hobby, and would rather spend their time doing something other than
learning about or even modeling antennas. There's nothing at all wrong
with that. Those folks won't find many of my postings to be interesting,
and won't read them, which is fine. And, like I did for a long time,
they'll put up plenty of antennas that work well enough -- and even from
time to time one that works exceptionally well. But I hope my postings
will be useful to those people who are interested in learning more about
antennas and/or who enjoy squeezing more performance out of them. And I
learn from this, too!

Learning about antennas doesn't diminish your ability to experiment and
successfully create working antennas. What it does is to give you more
tools, so you can -- if you choose, but only if you choose -- make an
antenna do what you want, rather than putting it up and settling for
whatever it does.

Roy Lewallen, W7EL