[GreenKeys] Atlantic Research Model # DMS-3C-10 Distortion Instrument

[lobasa]

Hi Gang,
   I came across an Atlantic Research Model # DMS-3C-10 Distortion 
Instrument.   The only thing
I can tell you is it runs off a 22.5 v battery.   Strange thing is it has a 
THREE prong connector with
three wires.  Does it run off another battery?    I can wire up an alternate 
power supply.
  Anyone who has the manual I would appreciated a copy.
  I have checked the US Patents and one of the Patents has two battery 
voltages on is 22.5, and
the other is  -18 volts.
  Of course the patents listed may not be exactly what is in the Distortion 
Instrument.
                                                 Any help would be 
appreciated,
                                                  James Tanton