Not all transponder antennas need a ground plane, only monopoles do. I
use the L-2 dipole antenna on this page: http://www.advancedaircraft.com/
inside my fiberglass ASW-19 tail cone. It works great with my Becker
ATC 4401-175 and was very easy to install.

-John

Paul Remde wrote:
Hi,

I was thinking the same thing. I believe that a ground plane would be
useless inside a carbon fiber glider. However, the same is true for any
other type of transponder antenna. They all should have a good ground
plane.

Paul Remde

"brianDG303" wrote in message
...
Is there a downside to mounting on a ground plane inside the fuselage
of a non-carbon glass glider?