You can plug your transponder into any open channel on your receiver since all it needs is power. Just be sure to plug it in with the correct polarity (positive to positive, negative to negative). The red wire is + and the black is -. Usually the outward most direction of your receiver is -. If you don't have any open channels, you can get a y-harness and split the channel into two. Traxxas makes a y-harness, not sure of the part number though.