RCA (Phono) Connector The plug's 1/8" by 5/16" prong connects the signal wire. The outer shell is ground, which connects to the sheath that wraps around the signal wire. See coaxial cable.

75 ohm. Get RG-58 or RG6 coaxial cable, and then get a set of strippers and an F or S fitting crimper. RCA fittings are about $2 each, and do not require soldering. RG-58 is 50 ohm. RG-6 is 75.