rq3 wrote:
Marco, I installed a Garmin GTX320A as a replacement for my old Narco
using the Garmin adapter. The installation took all of 5 minutes, the
adapter is invisible (looks like a custom install), there is effectively
no warm-up time on a 100% solid state xponder like the GTX320A, and I
have had no complaints from ATC.

You WILL likely still have warm-up time for your altitude encoder, and
make sure your coax and connectors meet Garmin's specs.

Thanks. Did you get a 337 and retest it for certification? If so, how
much did your avionics guy charge?

Marco