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1994-06-05
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4KB
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83 lines
SUBJECT: o Hidden Apartment HF Antenna
Bottom floor dwellers have some advantages over dwellers on other floors
concerning HF antennas. Single unit condo & PUD dwellers fall into this
area.
Dwellers in the mid-floor(s) have it the toughest. And top floor dwellers
have other advantages the first two don't.
HF antennas are large and trying to hide one can be like trying to hide an
elephant. Many hams try different configurations, snap together antennas,
wires, and flag poles to conceal their antennas. Some work out, but most
get caught in the end.
First, let's look at what you can and can't have. Most restrictive housing
areas have a long list of items you can't have. Clothlines, TV antennas,
sheds, flags, BBQ grills, etc. And most of all, the all important HF
antenna. It has something to do with nice surroundings.
Make a list of these items and place them in a column on the left side of
the page. Next, list what you can have and list them in the center of
the page. Next, list the items that are readly available in the area of
your home. Such items are trees, gutters, vents, fences, etc. Look closely
and don't leave anything out.
A hidden HF antenna must be just that, hidden to the naked eye, even at
a point blank range.
Next, list the areas that you have a ready access to. If you can get to the
roof, write it down. How about the attic, basement, trees, etc, without much
notice by your neighbors. Most HF antennas are discovered not because of
their design or placement, but rather a neighbor spies the ham installing
the antenna or at least doing something out of the ordinary.
EX: Creeping around on the roof, on a Saturday afternoon, is going to
draw attention. Flinging wires over trees is sure to draw some attention.
The big point here is not to install the antenna by looking like your
installing an antenna or doing something out of the ordinary.
There are some new designs out on the market such as PVC vent pipe antennas
for 2m. But for now we'll stick to HF. Most contracts for condo / PUD
dwellers will allow bird feeders. And even apartment dwellers on the bottom
floor can benifit from this design.
I'll give a brief description here of the Bird Feeder antenna and discuss it
further in later postings. The Bird Feeder HF antenna is a vertical cage
wire antenna. A 'What?' you might ask. Imagine if you will eight flexible
wires, evenly spaced in a circular pattern, much like a ground plane. Draw
these wires vertically to form a wire 'tube' and connect them together with
a ring at the top. Now imagine these wires inside a telescoping PVC mast.
Top that off with a bird feeder. Now, instead of a ground plane system with
radials you have to put in (the neighbors are watching), you have this
'wire tube' constructed as a vertical dipole. At 10m, the Bird Feeder
antenna is a mere 17' tall when raised. What would the neighbors say? Or
for that matter the manager?
"I raise it up for the birds to get into and it keeps the squirels
out too. And look, I can take it out when I'm not using it or the weather
is bad. Boy, I really like watching the birds from my window. Did you know
that ..."
And then go on about some rare, but not unbelievable birds that frequent
the feeder. Buy a book on the subject with some pages tagged to show them
what you've seen so far. At worst, they'll think you're a flake and leave
you alone. Next, go in and tune up 10m and catch some rare DX instead.
What do you have to actually put into the ground? Your coax and a PVC
pipe to hold the mast up. Make it low in the ground and cap it so the
mower doesn't take it off. For the most part, you can leave it up.
But do remember to put some seed in the feeder once in a while!
I'll give the details next posting and tell you about another right out in
the open totally hidden antenna.
This one is getting a bit long.
-WS