Pretty weird of TV manufacturers to leave out a coax connection on a TV when more people are cutting cable and going to free Over-The-Air antennas. I guess they figure the little savings on having an ATSC tuner is a good idea. Most people have 'Cable Boxes' with HDMI out, or some other kind of HDMI feed.
You would need to buy an ATSC external tuner (
* LIKE THIS * ).
It would work for local OTA reception off antenna, and probably work with most cable channels is signals are typically encrypted on modern digital cable systems, and the set-top box must be activated by an activation code sent by the cable company before it will function