Hi

I instruct and would normally use a buddy box system if possible.

The instructor holds a spring loaded switch to pass control to the pupil as soon as the switch is let go of the instructor regains control. this is far safer than passing the transmitter back and forth, your plane is far less likely to crash. When practising landings and take off if you get it wrong theres not much the instructor can do about it without a buddy box

When i wrote my previous post i was under the impression that the dx7 could be buddied to other tx types. but having downloaded the manual it suggests that it is only other buddyable to other spektrum ones.

I have seen a site on the net which gives details of how to wire virtually any tx to any other tx no doubt in time the same will happen for the dx7.

simon