Can anyone here tell me if the King KLX135/A GPS/COM is capable of
outputting serial RS232 data in a standard format (like NMEA-0183) that
is compatible with the TruTrak/DigiTrak autopilot? The TruTrak docs do
not mention the King GPS units by brand, only the Garmin and
Apollo/UPSAT brands. I almost find it hard to believe that King
wouldn't have made the KLN35/35A and KLX135/135A units not able to
output an industry standard data stream... but on the other hand it
wouldn't surprise me either.


From a quick look at the install manual dated August 1995, its a standard
King/Aviation format output using RS-232. It's not NMEA. Garmin stuff like
430/530 and older Garmin things like the Apollo/UPSAT also output
King/Aviation format, so if the TruTrak works with them it should work with
the KLX135.

The KLX135 uses the extended sentence format that includes all flight plan
waypoints except when its in OBS mode. The sentence is transmitted once
every 2 seconds. The serial port setting is 9600/8/1/N.

The output is semi-human readable kind of like NMEA, so it can be
instructive to pipe it into your PC if you want to record your flight or
troubleshoot something.