April 1 2014
The Amateur Amateur: April Showers Bring May.. Antennas?
By Gary Ross Hoffman, KB0H
A lot of stuff has fallen from
the roof of my house. I've dropped a lot of it myself. A veritable
hardware store of nuts and bolts have escaped my grasp while up
there. I could hear them going skitter-skitter down the slope, but
there was no way to intercept them and prevent their suicide dive off
the roof and into the unknown. The occasional connector, tie wrap,
and even a roll of weather sealant have also made similar getaways.
First inkling of a strange phenomenon
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It was definitely a radial element!
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The rest of the antenna emerges
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Tools I can usually intercept.
Most of the other items get dropped, so they have momentum before
they even hit the shingles. Tools, on the other hand, are usually
sitting there quietly, giving no indication that they're
contemplating a departure, when they decide to abandon me and run
away. Fortunately, they have to overcome inertia, and I hear their
movements before they build up much speed. Also, I've gotten smarter
about where I put them, so they rarely get away.
Just about everything that does
make it off of the roof just disappears. Logic says that they should
land on the ground somewhere, but I can never find them. I don't know
if it's bad luck or if some different rules of physics apply to
Amateur Radio rooftop projects.
I can't say that
nothing
was ever found. Indeed some antenna parts were discovered when my
wife Nancy mowed the lawn one day. Those weren't items that I had
dropped, though, they had been blasted loose during hail storms. As a
ham herself (N0NJ) Nancye recognized what they were and handed them
over to me. I stored them in the basement. I knew that eventually I
would have some compelling reason to go back up on the roof. I would
take the loose parts back up with me then and see if they could be
reattached.
Now I think we should have just left them on the lawn.
You see, some of those lost items have started to sprout.
At first I didn't realize what
was happening. I thought the tiny metallic object in the midst of the
iris and ivy leaves was a remnant of some old utility company grounding rod.
There are several of those poking out of the soil. But when I
investigated further it became evident that it wasn't a grounding rod
at all. It was a radial element of an antenna!
Well, you can imagine my
surprise. We have a difficult time getting
grass to grow. The
soil in our yard is absolutely rotten. We tried laying down topsoil.
We spread just about every fertilizer available. We've seeded the
lawn with special “hardy grass” and have gotten nowhere.
And now the yard was budding antenna parts.
Maybe the soil was good for something after all.
Or maybe it was climate change, I
don't know. What I
did know was that this was a fascinating
phenomenon. I watched the tiny stalk grow day by day. I wondered what
it's final form would be. When should I consider harvesting it? Would
it wither and die if I left it there too long?
Horticulture books were no help.
Not one of them mentioned dipoles, let alone beams, discones, or
anything more esoteric. Amateur Radio literature had plenty to say
about burying radials but nothing at all about what you could expect
to germinate. Even Googling “growing antennas” only
resulted in mentions of the 60s TV show
My Favorite Martian.
It looked like I was on my own.
I'd have to keep an eye on the antenna element and keep a record of
its growth.
Darned if I could figure out how
to enter it into
Logbook of the World, though.
After several days I got
another surprise.
More parts of the antenna were emerging from
the iris. It wasn't an antenna element that was growing, it was a
complete antenna!
This shouldn't have come as such
a shock to me. After all, I knew that some animals could regenerate
lost limbs. And as we all know, modern radios have regenerative
receivers. It's only natural to assume that an antenna system with a
low Standing Wave Ratio would benefit from the transceiver's
regenerative capabilities, right?
Then another thought occurred to
me. The antenna growing out of the irises was the result of a part
accidentally falling into the garden. What if I
deliberately
planted something? How much would be necessary for it to take root?
Would it require an entire element, or would just a sliver do? How
complicated an antenna could I expect to grow? I already had a
discone blooming, could I cultivate a big honking HF antenna? If so,
I'd better dig it up and sell it while it was still a seedling, there
definitely wasn't room in my yard for anything like that.
The concept was staggering. It
gave a whole new meaning to the term “antenna farm”. I
wondered if I would need to try to get my property rezoned, and if
so, as agricultural land or as a scrapyard?
I spent so much time watching my
little antenna grow that I'd completely forgotten that numerous
objects had also tumbled into the
front yard. When that
thought finally popped into my head I ran around to inspect the area
where most of the roof-escapees should have fallen. At first I didn't
see anything. But then I spotted a glint of something in the ivy.
Yes. There was definitely something metallic in there.
It was a screwdriver.
A screwdriver in the ivy.. just a coincidence??
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At first I was puzzled. I'd
figured out how an antenna could regenerate, but a Phillips head
screwdriver? That didn't make any sense at all.
Or maybe it did.
Perhaps being in contact with the
antenna, which was in contact with the coaxial cable, which was in
contact with the transceiver, which had a regenerative circuit....
Well, maybe not. It may have just
been a lost screwdriver that I'd stumbled across. I wasn't sure, but
just in case it had actually
grown there, I left it in
place. I will check back in a few weeks to see if it's still merely a
screwdriver or if it has blossomed into an entire toolbox.
In the meantime, I am fertilizing the irises with nuts and bolts.
Now that I think about it, many
years ago my grandfather had buried old radio parts in the yard of
his suburban home in Florida. We all knew why he did it. Florida was
going through landfill problems at the time and all sorts of
stringent waste disposal laws were being passed. Granddad was frugal.
He didn't want to pay the surcharges and extra fees, so he just dug a
hole when no one was looking and dumped in his old electronic junk.
Or so we thought.
Now I'm wondering if he knew
something the rest of us didn't. Perhaps he was aware of the
phenomenon that I'm now experiencing. Could it be that he really
expected to grow a crop of new radios? Is so, he was disappointed.
All that came up were oranges.
