ORIGINAL: bigedmustafa
JR and Spektrum equipment often requires both radios or boxes to be powered up and in the ''on'' position. Some radios, like the Spektrum DX6i, won't work if you try to buddy box them with a standard trainer box or sport radio; instead they require a second computerized transmitter that must be programmed identically to the first to work as a trainer box.
I have a DX6i TX and am teaching a buddy how to fly with a buddy cable. He has the PZ Corsair RTF that came with the DX5e. His TX must be OFF, not on when the cable is hooked up. No computerized controls on the DX5e, just High/Low rates. It works just fine. What I did was to flip the trainer switch on my radio and watch the control surfaces while he held the plane. Adjust trims on the ground until you see no movements from any control surfaces when the trainer switch is flipped. It works great, and he's actually starting to learn to fly!!!