For what it is worth Schempp-hirth are mounting the transponder antenna in the fin on the Duo Discus. Right next to the
radio aerial. I presume the same applies to the Nimbus 4D that uses essentially the same fuselage.
Apparently there is lots of space for a good dipole antenna, and the foam cored glass structure is not opaque to the
frequencies used.

Nothing external to get damaged but heaven forbid you should ever have to work on it...

Presumably it is not something you could retrofit (for the same reasons you would never want to have to repair it).

Bruce

Tim Mara wrote:
I strongly suggest you DO NOT but the blade antenna's!....
ever if there were some small aerodynamic advantage (I doubt it could be
measured at any glider speeds anyway) but these are very expensive and they
are easily damaged....
I offer blade antennas, the "preferred" simple and cheap stub antenna's and
the composite dipole antenna's..I've had several buyers of the blade
antenna's break them (they aren't typically very happy when this happens).it
doesn't take much effort to damage the composite blade antennas since they
are essentially a tiny wire on a thin metal plate with small (6/32) screws
in a very nice looking shark fin that is mostly filler (putty) with a thin
composite shell..
best regards
Tim
Please visit the Wings & Wheels website at www.wingsandwheels.com

"5Z" wrote in message
...
Any aerodynamic thoughts on the two available choices?

My ASH-26E came with the stub mounted just behind the wheel. Every
now and then it catches on the trailer, so I just straighten it, no
big deal.

An ASW-24B in our club is about to get a transponder and the factory
recommends the installation to be part way up around the fuselage
above the rear gear door hinge - looks like just behind the oxygen
bottle.

The blade looks cool, but is it really any better aerodynamically than
a $20 (http://www.aircraftspruce.com/catalog/avpages/
ted_transponder.php) stub?

-Tom