teufelhundin,

Using a JR rx is easy but requires hacking the rx. Remove xtal and 4 screws on rx side, pry lightly and then wiggle rx out. Using cutters and small scissors, cut the plastic part of the 4in1 down level with the back of the ESC side. This leaves 2 3 pin female connectors exposed. The top connector is the throttle input to the ESC with the black wire (return) being on the left side. The bottom connector is the rudder wich goes to the gyro and tail mixer. Using 2 each 3" servo extenders (remove outer covering over male pins VERY carefully to allow plugging in those 2 connectors side by side) connect the JR rx to the (now) 3in1 rudder and throttle signals. This completes the conversion to a JR rx but using the brushed controllers for both motors. I do not know how to convert to brushless tail motor, but this is the way to use another rx. I converted to brushless main motor using CC25 and use the existing gyro and brushed tail motor which uses a "Y" cable from the throttle output to both the new CC25 and the throttle input of the 3in1. Flies great.

Cheers