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Shockley tested a prototype field effect device. But results were small
and disappointing. Before the importance of a small distance (0.002 in)
between thin wire electrodes (0.005in diam) was established, a useful
bipolar device was achieved with a wax coated metal collector point,
surrounded by a liquid emitter electrolyte placed on an n type silicon
surface. Its bandwidth was less than 8 Hz.
Soon however (Dec 47) the electrolyte was ditched, and a polystyrene
holder with a piece of gold foil on its narrow face, neatly divided
with a razor cut, was applied to a germanium base.
This was the jackpot:
x100 gain, and frequency response clear up into the audio band.
This was called a point contact device. Junction devices came later, in 1950
^^^^^ ^^^^^^^.
Brought to you as a courtesy service of Nitpickers Inc.
Ref: Bardeen, Brattain, Letter to The Physical Review, July 1948.
brian whatcott <inet@intellisys.net>
Altus OK