Fox
Hunting
People
have been asking me what is the best kind if equipment for radio fox
hunting. Here are the most popular types of direction finding
equipment.
1 )
Directional antenna
2 ) Handy Finder
3 ) Tinfoil tube
4
) Paper clip
Directional Antenna
The directional antenna is the most useful peace of equipment.
It
can be any type of beam antenna. To use it you just point. A three or four
element beam would be the best for direction finding. Anything bigger
gets to hard to carry around. You connect it to your HT (hand held
transceiver) and use the "S" meter to work out the direction of the
incoming signal. By pointing in one direction then slowly turning the
beam around, your "S" meter will move up and down. At the "S" meters
highest reading, the antenna will be pointing in the direction of the
incoming signal.
The biggest drawback you'll have when using a beam
is that the closer you get to the transmitter the stronger the signal
gets. At some point your "S" meter will max out. This is where you will
have to use some kind of attenuation to reduce the signal strength so
you can see it on you meter. I'll get into attenuators later.
The
beam antenna is a long to medium range peace of equipment. The closer you
get to the transmitter, the harder it is to get a
bearing.
Handy
Finder
The Handy Finder is
a good medium to close piece of equipment. It will work at a long range as
long as the transmitter is sending a strong signal. It uses two antennas
to receive the signal and adds a tone to the incoming signal. By
rotating the antennas the tone comes and goes. The idea is to rotate the
antennas until the tone is gone. At this point both antennas are at the
same distance from the transmitter. You get your heading by looking
perpendicular to a line from one antenna to the other. The biggest
problem with this is that the transmitter can be in front or in back of
you. You'll have to take readings from at least two places some distance
apart. A good feature is that it gives off a tone. You don't have to
have an "S" meter on your radio.
Tinfoil
Tube
The tinfoil tube is a
short range-tracking device. By lowering your HT (with a rubber duck
antenna) into it you block the signal. This is a form of attenuation. By
moving the HT up and down inside of the tube, you can weaken the signal.
Then you turn around in a circle. When the signal goes away, the
transmitter is behind you. What you are doing is weakening the signal
enough so that when you turn around, your body blocks the rest of the
signal. This is a short to mid range tracking device and takes a lot of
practice to make it work.
Paper
Clip
You may wonder how a
paper clip can be used to find a transmitter. Well, it's an antenna and
attenuator at the same time. It works best a short range. By taking off
your HT antenna and sticking a straightened out paper clip in its place
you have an antenna that has no gain at all. Then you turn around in a
circle. When the signal goes away, the transmitter is behind you. By
bending the paper clip in odd ways, you can get a little directional
antenna. Add this and body blocking and you'll get in closer than you may
want to.
As I mention above, attenuation is most important
thing in tracking the transmitter.
If you are using a beam antenna,
you may want to invest in a line attenuator. This is a box the goes into
the line from your antenna to your HT. It has several switches on it. As
you flip the switches you are shorting some of signal to ground. The
more switches you turn on the weaker the signal gets.
There are
other more elaborate pieces of equipment you can get. But the cost is high
and they may or may not work in all the hunts you go out on.
It
has been my observation that the cheapest equipment works very well. And
it only take a little more practice to make it work.
Bob
KA3VKU