The connector needed is called a Wander Plug. An obsolete type that essentially consists of a 1/8" split pin with a collar and screw on plastic cover to retain a single wire.
All is not lost however, take a piece of insulated wire about 6 feet long, (something like one core of a length of lighting flex), strip one end back by about half an inch (13mm) then use a matchstick to poke it into contact with the metal inside the socket marked "AERIAL" ( not Ariel- that's the name of a mythical character), the one with the scuffed circle round it. That should get enough signal to be able to receive something though in a modern environment full of electrical noise from wall warts and other electronic equipment the results may be disappointing, along with limited choice of stations!
Edit: What Paul said only a bit slower
