Brass wall plate connectors

[Tim R.]

Originally Posted by MadMan

Is the radio one a 1/4" headphone jack? If the family was listening to the radio in the living room and you were being antisocial, you could plug in your headphones in your bedroom or whatever, I'm assuming.

Close, but not quite. While it is a 1/4” jack, it’s not intended for audio. The sleeve connector is grounded and the tip wired to an antenna. The radio’s antenna and ground would interface with it via a phone plug.

If you look at the back of the plate you’ll see that the tip shorts itself to the sleeve when there’s no plug inserted. No doubt this was for protection of the house against lightning strikes.