If you're looking for a way to send video AND audio data to a TV, either 1. Use a vid card with RCA video out, and use your sound card's line out to go to the TV,
or
2. Use the same setup above, but run the video and audio signals into a separate RF modulator available at most stores that sell A/V equipment. (about ฮ)
I actually do #2 at my house... we don't have cable, but the house is wired for it. So I got an RF modulator and plugged it into a spare cable outlet... I can play divx movies and watch them in a different room. Just tune to channel 3