Ultra-High-Frequency Triode Oscillator Using a Series-Tuned Circuit

As the conventional triode oscillator is applied to higher and higher frequencies, one or both of two phenomena finally prevent oscillation. These phenomena are transit-time effects and self-resonance of the tube elements. The analysis described in this paper refers these effects to the resistance and reactance requirements of the tube upon the external circuit. In those instances where a given triode is limited primarily by the reactance effects, due to large lead inductance, it is shown that the self-resonant frequency of the tube is not the upper limit of oscillation if one departs from the conventional parallel-tuned circuit and uses a series-tuned circuit instead.