These are the steps we have to follow to change from Cable to Antenna with our Toshiba:
1. Press the MENU button to open the Setup menu on your remote.
2.Highlight Installation, and then press ENTER button.
</span>A new set of Installation menu icons appears.
3. Open the Terrestrial menu, highlight Input Configuration, and then Press ENTER button.
4. Highlight ANT/CABLE In and press the right or left arrow buttons to select the input source
</span>Cable or Antenna.
5. To save your new settings, highlight DONE, and then press the ENTER button.
Hope this helps, we have the Toshiba model 32X120U.