Bill Boyd
Well Known Member
For anyone with a legacy EZ-Pilot system installed in their plane who hears the siren-call of coupled approaches, VNAV and all the added features that Trio has put in their ProPilot model that were not in the original EZ's, let me give you a heads up on a gotcha that could get ya if you have the older, black NavAid roll servo that Trio sold with their first run of EZ-Pilots (or if you cheaped-out and found a NavAid on eBay, and told Trio to keep their golden box and you'd keep some shekels).
The NavAid servo has only three wires, the Gold Standard servo has four. Either will work fine with the EZ and Pro systems, but you have to watch the wiring convention. The Gold Standard wires are GRN, RED, WHT and BLK. The Navaids use GRN, RED and BLK - no WHT wire. Here's where you have to pay attention: The RED and BLK wires have the same function for both servos, but the GRN wire on the NavAid, for PWM data, is equivalent to the WHT wire on the Gold Standard servo, and is wired to pin 2 (not pin 3) of the DB-37 connector on the ProPilot control head. Do this wrong and you won't let any smoke out, but it also won't work. Your NavAid servo will energize and resist stick movement, but it won't respond to the autopilot in calibration or flight modes.
I don't think this is addressed in the ProPilot documentation, and until it is, this is relevant to your interests if you are upgrading an older system and keeping your legacy roll servo as I did.
-Stormy
The NavAid servo has only three wires, the Gold Standard servo has four. Either will work fine with the EZ and Pro systems, but you have to watch the wiring convention. The Gold Standard wires are GRN, RED, WHT and BLK. The Navaids use GRN, RED and BLK - no WHT wire. Here's where you have to pay attention: The RED and BLK wires have the same function for both servos, but the GRN wire on the NavAid, for PWM data, is equivalent to the WHT wire on the Gold Standard servo, and is wired to pin 2 (not pin 3) of the DB-37 connector on the ProPilot control head. Do this wrong and you won't let any smoke out, but it also won't work. Your NavAid servo will energize and resist stick movement, but it won't respond to the autopilot in calibration or flight modes.
I don't think this is addressed in the ProPilot documentation, and until it is, this is relevant to your interests if you are upgrading an older system and keeping your legacy roll servo as I did.
-Stormy
