I am far from an expert on this. I have only been flying 2 years. Since no one has replied yet I will try to help. First of all.... I have a Futaba transmitter, and have a Hitec receiver, and servos. I have mixed the servos, 1 Futaba and 4 Hitec etc. The main thing is that the plugs that go into the receiver from the servos will be compatable with female plugs in the RX (and of course has the same channel # [img]i/expressions/face-icon-small-happy.gif[/img]. This is FAR from a COMPLETE answer.... and I am sure someone else will add to this and give some much needed technical info. Different brands of servos have different colored wires. Hitec gives you a sheet in their servos to show the different wiring colors. Futaba has a "J" plug.... which has a little tab on one side of the plug. This won't fit into some extensions or receivers because of that tab. Just use a #11 blade and trim off that tab, and the actual plug is a perfect fit. Just make sure the plug is not "flip flopped". Check that the color code of the wires is the correct match. Once I have everything plugged in correctly....brand name match or not, I put a dab of "White Out" on the matching sides of the plug and receptacle. (usually the black wire side, although it doesn't matter.... as long as you STAY consistant on all wires and all models).
It makes it easier to plug in without getting it wrong, or studying for 5 minutes each time. .... lownslo...... Bob

PS.... I don't know much about JR..... all I know is Hitec and Futaba CAN work together. (MAYBE .. Airtronics too ???)