The Hammond Organ Company made these small cut-away “organs” to demonstrate how the Hammond Organ produced the tones. Only the right most key functions but both drawbars do work. The unit is powered by two “D” cell batteries operated through a momentary switch. The output of the demo unit can be put through a small amplifier so that the tones may be heard.
Note “Hammond” name on front edge… Tone wheels under and to left of keys
The tone wheels produce tones 3 octaves apart
Tone wheels from the top… note the pick up coils.
Only two contacts are connected in this demonstration model… Intensity resistors for drawbars on left