I elected to mount the transponder in the empennage. This will distribute more weight aft. Also it frees up space near the instrument panel. I needed to run coaxial and a wiring harness back to this location. The transponder antenna is under the pilot's seat. I used a Wellen mounting tray and attached it to the stiffeners along the left side of the fwd empennage. It is out of the way and easy to service in this location.
