If I remember correctly the device had 300 Ω twin lead wire connected to it. The homeowner said that it was for an old roof antenna. Are you saying that these weren't used to television at some point?
300 ohm twin lead is a balanced feed circuit and the center of the antenna element could be insulated (dipole) or optionally grounded (folded dipole.) It was used for TV, FM, and some Ham bands.
If properly mounted (almost impossible) it has a lower loss over distance than coax.
You could use this socket for twin-lead if it has two poles on the aerial side (hard to confirm from the picture.) The three pole variant may have been produced for awhile, but never, AFAIK, combined on a time with power.
If it has only two poles total it is old AM/shortwave and using it for twin-lead would violate its markings but work just fine if you do not connect a ground wire.