Al Stein said:
I'd also consider adding an external power supply through the appropriate pins instead of using the transmitter's own batteries. (I notices that the Tom's site that Askalon referred to uses external power. It's a good idea I've been meaning to do for mine but haven't gotten around to.)
Yes for Futaba you can do that which is great, but for JR your stuck to using your own batteries. This is just an FYI for those that have JR and see this and say oh cool and try to get one so they won't be disappointed to find out it is not possible.