jessekib,
That means that you'll be using a JR box as the master and a Futaba as the buddy box. That means you CAN use the Hanger9 cord that is available. However, that's only if you use a Futaba buddy box that has batteries in it. Check with your instructor to see if he has a transmitter can use this way. And make sure you remove the crystal or module from the Futaba box before you turn it on.

dicksoucy,
Not true. I've used many differnet types of JR boxes together with no problems, everything from a basic Quatro 4 to my 13yr old x-347, to newr 8103's. And I've mixed various Futaba (and Hitec) boxes together as well, with no problems there either.

The only issue is that when you transfer control from the master box to the student, you transfer everything. (*most of the time. more on that in a moment). That means that all rates, end points, subtrims, etc go to the buddy box. If someone "toned down" a plane by using duel rates, expo, or EPA on the master, then tried to fly the plane with a non-computer buddy box, they'd get nothing but linear 100% rates on the buddy box. Not a good thing. This is why students with wiz-bang fancy computer radios should turn everything off and make sure every thing is at 0 (trims, expo, etc) or 100% (rates, etc), unless they have their own programmable buddy box as well.

On the flip side to this, if you have a computer radio to use as a buddy box, you can use it's rates or expo to give the student less throw than the instructor has, a good thing. If you're a student, and you have 1 non-programmable box, and 1 computer radio, set your trainer up on the dumb box as the master. The instructor can handle the lack of programmability, and you can use the programming to help the student.

* some transmitters can transfer only some channels to the buddy box. While I actually own a radio that can do this (the old x-347, much to my surprise), I've never used it, and I have no idea how it works, or how it affects things like rates and trims, never mind mixes. (mixes, though, you don't expect to find in a buddy box much anyway).