My RF/G2 printer port interface cord has developed an intermittant connection at the plug that goes into the buddy cord outlet on my JR transmitter. I bought a buddy cord to cut and splice onto my interface cord. The interface cord is a co-axial with a white sheath surrounding the center wire, around which is the outer wire and insulation. Unfortunately, even though the buddy cord looks like it would be a co-axial, it is not. It has three individual wires inside -- a black, a red, and a brown. Which of these wires do I splice onto the interface wires??

Any help would be very appreciated,
John