It is an APIS. The antenna is in the trailing edge of the rudder due to the
fuselage, vertical stab, and most of the rudder being carbon fiber.

I do have an inexpensive VSWR meter. I also have a 50 ohm dummy load (left
over from thin wire ethernet days....). I'll check my meter with that.
I haven't installed my Microair radio in the glider yet. I did a check
after installing the wiring and connector using my handheld ICOM and the
VSWR was a little less than 2 then. Looks like I should be okay.

John