Once upon a time, I tried many different com antennas on an HP-18, an
all-metal sailplane with fiberglass nose and turtledeck. The most
effective antenna was a bent 1/4-wave whip mounted over the aft
fuselage.

For the HP-24, I install a 1/4-wave dipole inside the rudder, but that
is not a realistic possibility for the Lark.

Thanks, Bob K.