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Schematic of the valve oscillator circuit
developed by
1 - E.H. Armstrong
2 - Edwin Colpitts |
The vacuum tube oscilator generated
continuous waves at a single frequency, unlike its predecessor,
the spark gap, thus permitting communication over a single
channel. Using positive feedback and the triode as an
energy pump, it provided a sign-wave output at the resonant
frequency of its tuned circuit. Several individuals independently
invented the circuit in the beginning of 1910, notably
Reginald A. Fessenden, Edwin Armstrong and Edwin Collpits. |
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