I installed my Garmin GX-327 Transponder antenna. I selected the area beneath my pilot seat because of easy access in case of necessary maintenance. The transponder propagates ~200watts at 1090 MHz but I installed a doubler and the X-10 bottom skin should be providing enough shielding. The Garmin GX-327 Transponder antenna. is 36 inches from my Garmin 430 Comm 2 VHF antenna and just forward of the landing gear so I think the location should be satisfactory.