[MrFixr55]

Oops, sorry. I was thinking of stereo sources such as CD Player, MP3, etc., and adding a radio - aux switch and input. Many of my radios actually have these, including the Zenith H725, my RCA 1R91, 2 GE clock radios (turn the volume control CCW for phono, CW for radio from a center null position). Even my 14BT2 has a phono jack but no switch; tune to an empty spot on the dial). My 5T7 and GE S22 (RCA R7) have terminals for external phonos. The Phono assembly had a switch to select radio or phono. If the phono was not installed, a jumper is installed instead. The S22 is more complicated, as the biased detector's bias must be changed to make it into an amplifier stage. I have not found a good readable schematic for the phono - radio switch wiring. Another interesting thing is that RCA phonos of the 1932 vintage used a magnetic pickup that was developed in the late 1920s for the various Electrolas. The pickup put out a much higher voltage signal than current magnetic pickups or the GE RPX pickup introduced in the late 1940s or early 1950s.