Hitec and Futaba are compatable, Not so with JR. Jr uses a positive shift, Futaba and Hitec use negative shift. You can buy Hitec receivers that are compatable with JR but they must be special ordered. Always use a crystal designed for that particular brand, i.e. Hitec in Hitec, Futaba in Futaba and JR in JR as they are not usually interchangeable due to minor differences in the electrical designs of the internal oscillators. You can also buy aftermarket receivers from FMA that will be compatable with any one of the above, just specify the transmitter type when ordering the receiver. If you are new to the Radio Control stuff, you might want to check out www.torreypinesgulls.org/Radios.htm for a pretty easy to read tutorial on the different types or RC equipment and differences between PPM, PWM, PCM etc.