RE: Diode in 8UAF Super
You short the power line in the trainer cord to ground, and it goes POOF - or in my case just open circuit. Note to myself - don't try to put the antenna back in while the radio is turned on, it can hit the trainer jack and ground it.
[:-]
The power for the radio battery goes straight to the transmitter module, but has to go thru this diode to power the rest of the electronics - its main purpose is to allow the trainer cord to power the electronics without powering the transmitter.