D-100 Altitude Output to K-76A Transponder

[DuaneFamly]

Experimental. Just did first flight. Tower says their radar has no Altitude information from me. They read the transponder and Ident but they receive no altitude information. Verified wiring from D-100 to Blind Encoder then to transponder, power to encoder is good, so how can I verify that the D-100 is sending altitude info on the serial TX line?

 

[Dynon]

The serial ports virtually never break. It's most often be power to the encoder if there is no data, or one or more output wires that are not properly connected if ATC is seeing erroneous altitude.

Configuration-wise, did you check the altitude encoder format output setting on the EFIS? SETUP > ALTENC > FORMAT should be set to format 1.