How to Connect a Wii Using Coaxial Cableby Matthew Weber
The Nintendo Wii console comes packaged with standard stereo audio/video cables. Many older televisions will not have the inputs to support these cables, and only support a coaxial connection. Past Nintendo systems, such as the Super Nintendo and Nintendo 64, have had coaxial support from Nintendo directly in the form of RF switches and modulators. Though there are no official Nintendo RF modulators for the Wii, using a third-party RF modulator (see Resource) will let you connect a Wii to a TV through coaxial.
Connect the stereo audio/video cables from the Wii into the "input" plugs on your RF modulator. The location of these plugs will differ from model to model of RF modulator, but all will have clearly labeled input plugs.
Attach one end of your coaxial cable to the "output" plug on your RF modulator.
Connect the other end of the coaxial cable into the coaxial jack at the back of your television. Change the channel on the television to channel 3 or 4, depending on your modulator. Your Wii can now be be played via coaxial cable.