Download The Full February 2019 Issue PDF

You already have a transponder that transmits a dumb and blind signal in response to interrogation from other sources. Well, its not entirely dumb in that you can enter a four-digit base-eight (no 8s or 9s) code on the instrument and when the transponder responds to an interrogation, it puts that code and even your present altitude (to the nearest 100 feet) onto its outgoing signal. ADS-B Out keeps that but takes it a bit further.