I've had long discussions with the technical folks at Artex and other ELT
Manufacturers. Gliders and airplanes with carbon fiber do create so
additional problems when it comes to antennas. It is not possible to hide an
antenna inside these structures and a suitable ground plane is required for
any 406 mhz ELT.(Artex manual states the ELT requires a ground plane (metal
aircraft surface is typical) or can be made from metal tape 1" wide in a
minimum of 24" radials. or from 22 AWG wire, so obviously the fin of a
glider isn't going to allow you to meet these requirements. The ELT
antenna's are also supposed to be mounted with a (up) vertical
orientation...
Also I note that you say you have a transponder antenna mounted vertically
on the top of the fuselage.........this is also not a proper installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.
There are some high performance antennas (you can easily spend more on some
antennas than the cost of even a 406 mhz ELT!) that are more compact than
the Whip antennas but this doesn't completely change the requirement for
ground planes or proper orientation.
the Artex ME406 installation and operation manual is available from a link
on my web page http://www.wingsandwheels.com/page13.htm. Please look there
and you too can contact Artex and speak with their technical people for
additional advice.
I hope this is helpful
best regards
Tim Mara

Wings & Wheels
www.wingsandwheels.com


"E. Douglas Whitehead" wrote in
message ...
What are the issues and can they be overcome
with regard to installing either an ARTEX ME-406
with Whip Antenna or an ARTEX ME-406 with
Rod Antenna.

I have an ASW-27 WITH a transponder mounted
on top of the fuselage and no tail tank or
tail battery.

Natuarally, I want the antenna internal or located
to create as little drag as possible. The fin
is kevlar.

Is the 'possible'?

Thanks.

Doug Whitehead (EDW)

212-879-3131