[MrFixr55]

I can't remember if it was a Philco or an Emerson, but I fixed one that had an RCA style phono jack on the right side. On this model, when you plugged the phono into this jack, the radio would be disconnected, much like a headphone jack does.

I have 2 Zenith AM FM H7XX models, an RCA 1R81 and 2 GEs, all with RA Phone Jacks. Most have radio / phono switches. the 2GEs are mid 50s clock radios. Turning the volume pot CW makes the radio louder and the phono lower, turning it CCW makes the radio lower, and the phono input louder.