Stan's Demo Cell had a 0.090" Gap, which is 2.286 mm
In the Fuel Gas patent he says 0.0625", which is 1.5875 mm for a 4 inch cell
In the Circuit Patent he says 0.125", which is 3.175 mm for a 3 inch cell (the famous 5 gallons of water split per hour)
In the TB for the injectors he states from 0.060" to 0.010" which is 1.524 mm to 0.254 mm
The quenching circuit comes into effect at 0.025" to 0.015" which is 0.635 mm to 0.381 mm, or smaller
I wont show you any math just to keep things simple.
Suggestion for buying tubes: Stan uses thin wall tubes for the demo cell, outer was .750" OD, 0.035" thick, inner was 0.500" OD 0.049" thick, these are standard sizes you can buy, yes it was a typo in the drawing, he simply left out a zero, and for the inner and outer tubes, they weigh about exactly the same. Also, thin wall tubes are cheaper, and more likely to vibrate in the audio range.
