Clarification:

216 MHz is what we're using now. We're getting away from 215 because of
interference with digital TV.

Hi Folks:

I'm looking to make a directional antenna in the 215 to 218 MHz band (215 if
that's too broad), used for location of dementia patients who have wandered
away from their caregivers. I'm a volunteer with an organization that
locates these people. They wear a tiny transmitter which emits a chirp that
can be heard from 1-2 miles on the ground and 8-10 miles via helicopter.

I'm somewhat new to the program, and I'd like to do some investigation on my
own regarding antenna types that would be useful, and I hope you'll all
grant me a few questions.

My needs are this.... the antenna must be as directional as possible. It
must be most efficient in the 215 to 218 MHz band 215 is what our patients
are on right now, though after we fill up that range we have licensed
through 218 MHz. It must be easy for an individual to carry, and portable
enough to carry through any type of terrain. It must be shaped in such a
way that it's relatively safe and easy to use in an enclosed area, either in
a helicopter or a car. Currently the agency is using a 4 element Yagi,
which works well, but has the drawback of being a real eye-poker when used
in close quarters, and in fact the California Highway Patrol will not allow
them to be used in their helicopters because of that reason.

Now small antennas can be made I would suggest to those encombered by
restrictions
to duplicate the following assembly so they may rejoin the hobby.
Obtain a 1/2 plastic pipe.
Purchase two reels of dog fence wire which is pre wound twin wire
Solder the wires of each reel such that it is now a continuos wire.I
used the 20 gauge form from E bay($24)
With the joint at the back of the plastic pipe turn the right hand
side one loop and then the other side one loop but in the opposite
direction.
Procede until you have a wrapped pipe of say a 6 foot length.
Obtain a hula hoop from a store and remove the joining plug.
Push the windings off of the plastic pipe and slide it on the hula
hoop
untill it is full.Replace the plug and connect the transmission lines
to one of each
of the wound wires and solder together
the remaining two wires. Locate resonant points for all bands and
connect to a rotary switch of your choice
for connection for future band use.This antenna will be useable for ...

I found some coax in the garage called RG58C/U E50032 AWM style 1354. It is
silver coloured and not copper. Any one know if this coax is of good quality
not?

I want to use some for the Cobwebb antenna and I want to make some coaxial
traps for my wire antenna with it.

Thanks