Looking over my 152's logs, it appears the transponder has not been
inspected since the altitude encoder was installed, about 10 years ago. Is
it legal (not necessarily smart) to pull the circuit breaker, placard the
transponder as inoperative, and continue to fly until I get it inspected at
the next annual? I would be staying clear of class B and C.

FYI, the mode C is working fine.

Thanks for all comments.

Matt