Futaba T14SG Trainer Cable Power On Feature

If you own a Futaba T14SG transmitter, and possibly other Futaba models, you may have noticed that whenever the trainer cable is plugged into the transmitter the transmitter powers on even if the transmitter power switch position is off.

Although this may be a good feature for folks using the trainer port as a trainer port, in which case the trainer cable is only periodically connected, it is not good for me because I do not want to have to plug and un-plug the trainer cable all the time. My reason is because I want my DJI Lightbridge to be permanently attached to the Futabe 14SG since both are mounted to my transmitter tray.

I found out that the reason the 14SG powers on is because pins 4 and 5 are bridged inside the Futaba trainer cable connector. It was relatively easy to pry open the Futaba FF9 connector and un-solder the bridge. The Futaba FF9 connector housing snaps together with three small tabs that can be opened with a small flat jewelers screwdriver.

Here is a diagram showing the Futaba FF9 connector and the bridged pins. I have also included a male and female mini phone plug diagram in case you want to make your own adapter cables.

BTW: Remember to turn off your Futaba 14SG RF radio when using the DJI Lightbridge. You do this by holding RTN when you power on the transmitter then selecting RF OFF.