[amptramp]

According to the schematic, the FM coils are directly across the single-section parts of the tuning capacitor and AM and SW share the other part.  The bandswitch positions appear to be pushbutton AM tuning (where the switch is in the schematic), AM, SW and FM.  Pushbutton tuning only uses the rows of tuning capacitors on the bottom.  AM and SW use the large parts of the tuning cap and FM uses the small part.