[Texasrocker]

Hello etech! I ran across the same thing on a 36 GE M-50(?.. I think that was the mod#) tombstone for a customer a few yrs back,however, the knob for phono input control was mounted on the rear chassis panel next to old-style 2-pin phono input connection. Knobs matched perfectly as fnt controls knobs also. Looked like orig factory install, but wasnt included in my Riders schematic at all if I remember correctly. Thats been awhile ago, I just remember noticing it, very unusual on those model sets.
I recapped the radio,got it working fine, but never tried using the phono as I dont have one.
Seems there was a spot on the tuning dial condenser that had a simple contact switch (looked orig too), that when the tuning condenser up past 1700 kc engaged, applied the phono input (simple copper contact touch switch). I remember scratching my forehead after I noticed it, asking myself..whats this?!Then I remembered the phono input would be activated. I got hum from touching the + input phono terminal after restoration with switch contacts engaged, but never tried a phono. I figure the phono input would have worked if needed.? I also have a 1929 Fada mod KW console w/ (trf) chassis with the same type phono input jack, except no extra phono input vol control. If I remember, it was shown in the early Fada schematic, and that set even has the old early "flash-o-graph" neon gas type tuning indicator tube which predates Philcos shadowmeters.
Didnt mean to get off-topic here. Hopefully someone here can help us both on that mystery phono setup question!