Keyboard Encoder

[Steve Ridley]

I have a vague memory of a similar assembly in an Ondes 
Martonet or something of that vintage.  It used an iron core
moving into a coil to alter the inductance rather than a 
transformer action.  This worked sideways, so side-to-side 
movement of the keyboard altered the tuning of an oscillator
and gave pitch bend or vibrato.  Sounds like a splendid idea.

Anyone out there got an Ondes Martonet schematic?
Or a copy of the patent (too early for the IBM patent search 
engine by around 50 years).


Steve Ridley