ORIGINAL: Adui
Slave always has power off, even with computer radio, or so I was taught and every buddy box system I have read up on indicates.
The power "comes on" when you plug in the trainer cord, (at least mine does, all three radios I have work this way) but it does not power up the transmitter RF circuitry. So your computer control system is then on, and ready to interface with the master radio's transmiter circuit, but you arent sending an extra RF signal out to screw someone elses day up.
This is not the case with a number of JR/Spektrum buddy box systems. The buddy box requires its own battery and must be powered on in order to work. How each radio interacts with various other buddy box options doesn't always seem consistent from model to model, however, and our club is trying to figure out all of the details in order to best assist new pilots with JR/Spektrum radio systems.