RE: Servos Question
Frequency and "shift" most JRs are positive shift.(I have heard some newer JR radios are shift selectable)
Look for a positive shift, shift selectable or auto shift reciever. I have had good performance from Hitec recievers.
I should go a step further not knowing what JR radio you have.
You cannot use a PCM reciever unless your radio is PCM capable.