I'm posting this here hoping that other DIY'ers might be able to help - not sure if Home Improvement is the right place, but this seems the closest on Stack Exchange.
I'm constructing an antique radio out of scraps I can find on the Internet. I'm not sure what to make the dials do in the Philco 90.
Top dial - radio channel tuning
Right dial - volume
Middle dial - tone(?)
Left dial - not sure at all.. AM/FM? FM didn't come about until mid-1930s. Anachronism?