You don't need a stb for over the air hd, if your tv's are the 24" rca's. They have built in digital tuners. On our '08 the rear tv cable outlet wasn't connected behind the box in front upper cabinet. In the back of the cabinet you should have a plate labelled satellite tv connection. If any grey coaxial cables are connected, more then likely one of them is your rear tv. Wires only get connected to that plate if you have sat tv. Previous owner may have had a carry out or a dome on the roof. BTW if you have the original antenna on the roof, switch it out for the Jack antenna, big difference.