On the Oscillations Produced by Means of a Duplex Valve Oscillator

Abstract

The duplex valve oscillator, as the writer suggests to call it, is the valve oscillator containing two oscillation circuits as shown in Fig. 1. The natural frequencies are so much different from each other that the impedance of the one cirouit at the frequency, which is given by the constants of the other circuit, is negligibly small compared with th internal resistance of the valve.
In this paper is treated the stability of the oscil ation produced by means of such a duplex cscillater. For exsmple, when the capacity of the variable condencer in the high frequeney φ oscillation circuit is varied gradually, sudden change in the fr quency of the esci lation takes place at two points J1 and J2, as shown in Fig. 2.
Such a jumping phenomenon may be explained by taking into consideration the variation of the internal resistance of the valve, which is dependent upon the amplitude of the oscillating plate curr nt.
More vor, the writer considers the case, where two oscillations, one of high frequency and the other of low frequency, can build up simultaneously, and shows come experimental results obtained by means of a Braun tube oscillograph.
Some circuital arrangements of the duplex osci lator are shown in Fig. 16.