Bird Feeder Antenna
antennas are large and trying to hide one can be like trying
to hide an elephant. Many listeners 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 shortwave antenna. It has something to do with nice
So, what to do?
Make a list of all forbidden 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
Finally, 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 shortwave antenna must be just that: Hidden.
I should not be visible to the naked eye, even at a point blank
So, 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, especially without
much notice by your neighbours.
Most shortwave antennas are discovered not because of their design
or placement, but rather a neighbour spies the listener installing
the antenna - or at least doing something out of the ordinary.
For example 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
There are some new designs out on the market such as PVC vent
pipe antennas for 2m. But for now we'll stick to shortwave. Most
contracts for condo/PUD dwellers will allow bird feeders. And
even apartment dwellers on the bottom floor can benefit from this
The Bird Feeder
The Bird Feeder shortwave antenna is a vertical cage wire
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 neighbours 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 neighbours say?
Or for that matter the manager?
"I raised 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...
Bird Feeder Antenna - the details
This design sounds a bit far fetched, but it works. The
vertical dipole, inside the PVC push-up, is invisable. It moves
up and down and can be removed without drawing attention to the
fact that it contains an antenna. The flagpole design has some
problems. Not all PUDs, condos, or apartments allow flagpoles.
They represent a permanent fixture. Not all associations or managers
are that patriotic.
Although you can pack a good vertical in a flagpole, there is
the problem of radials. You can run the vertical without radials,
but that's another compromise.
The design for the Bird Feeder Antenna is very simple:
You can build the vertical dipole without much trouble. The dipole
consists of up to 16 wire 1/4 wave elements. There are eight on
each leg of the dipole. You may use less, it's up to you. You
know the bandwidth of a wire dipole and you know the band spread
on 10m. If you are a general or above, you will want the extra
wire elements to give you the bandwidth you need.
First, let's look at the PVC tubular mast / bird feeder
support. Most hardware and home improvement center have PVC tubing.
Like the steel counterparts, the mast will be graduated (large
at the bottom and smaller at the top. I'm not going to recommend
any sizes here as availability at your store is going to dictate
what sizes you will need. I will state the the top tube should
be 2" in diameter or better. You will need that size to support
the bird feeder and give the mast some strength (see example below).
| | <------- Attach upper ring
| | inside
|_| <------- Attach ring
| | inside
|___| <------- Attach ring
| | inside
|_____| <------ Attach ring
| | inside
|_______| <------ Attach bottom ring inside
elements are attached in a ring format, evenly spaced, in
a 360 degree pattern. Locations are noted in figure one. This
allows the dipole to be folded up when the mast is lowered. More
than eight wires on each leg of the dipole tends toward snags
when raising and lowering.
Dipole wire element sizes are calculated by 246/f Mhz. But I recommend
shorter lengths if eight elements are used. A balun can be inserted,
but is not necessary. I feeder coax is needed from the dipole
feed to the base of the mast. A UHF bullet (female to female)
to attach your coax to.
Installing the Bird Feeder
The base piece for the bird feeder mast should be one size
larger than the bottom section of the mast. The mast should be
able to side in a snug fashion, but not too tight. Since you are
installing a 'bird feeder', you shouldn't have any problem explaining
what you are doing. Simply lay the bird feeder and mast right
out in the open. Your nosey neighbors will know exactly what you're
doing (almost). The coax is the tough part.
Trenches are out of the question. Use a sidewalk edger (manual)
and make a thin cut in the grass. If you have other obsticles,
you will have to deal with that when you come to it. The object
is to do it when the neighbors are not going to notice. The thin
cut in the lawn will not be seen and will 'heal' quickly. A tricky
technique is to use a wheelblade on a handle. It will look like
you are using a measuring device. The cable can be laid into the
cut at dawn, when you are filling the bird feeder. Stepping on
the cut lawn on the way back seals the cut. Now you're in business.
Wayne M. Sarosi, KB4YLY, edited for online publication by Hermod
Pedersen, the Nordic Shortwave Center.