I was trying to use the cable that came with Realflight 3.5 for a buddy box cord between my Futaba 7C and my Futaba T4YF 72mh radio. I can get it to work with the power turned on the 4 channel (antenna and crystal removed). Will it work like this? If I got a true trainer cable, would it power the 4 channel radio also? In the 7C manual it doesnt say anything about having to power on the slave, and when I was training, I never powered on the slave either.