The LT works very similar to our previous units in that it requires a yellow composite video connection for the Closed Captioning. In order for the LT unit to work with Antenna TV or Coaxial connections, you will need an external tuner, cable/satellite box or converter of some sort or an old VCR; then connect the VCR to TVGuardian LT using the composite video cable (the VCR would need to be turned on when watching TV). TVGuardian will also only work with 1 TV at a time.