Have a trex 600 and using a futaba R146iP receiver with 6 channels. Have the channels connected to the following:

channel 1 - aileron
channel 2 - elevator
channel 3 - esc throttle
channel 4 - rudder/gyro
channel 5 - gyro gain
channel 6 - pitch

have no additional channels for the BEC connector. Any help. Have read that a Y-connector is necessary to plug to the channel 3 with the throttle. Also cutting the red wire from the BEC to the Y-connector. But not sure.