Operation of the modulator tube in radio telephone sets

Operation of the modulator tube in radio telephone sets

Year: 1921

The modulator tubes of radio-telephone transmitters used in commercial and military sets operate essentially as aperiodic power amplifiers of speech currents. The load on these tubes is determined approximately by the volt-ampere characteristics of the radio-generating circuit, as measured at its plate power-input terminals. At speech frequencies other effects occur as follows: (1) Current to the modulators and the generating circuit in parallel is supplied through an audio-frequency choke coil. The finiteness of the inductance of this coil results in an inductive component to the load. (2) The wireless generating circuit contains suitable impedances to prevent consumption of h.f. power by the modulator tubes. These and other parts of the generating circuit may produce reactive com