| 摘要 |
A communication receiver for receiving speech and sequential control tones wherein a pulser circuit is provided and rendered operative in a predetermined manner to produce a pulse pattern for intermittently rendering the receiver operative. The receiver comprises a tunable filter for selecting the desired control tones and detector circuits for detecting said control tones to provide a plurality of control signals. Said control signals are employed to control the pulser circuit to render the receiver operative to receive speech and control tones in a predetermined manner. The tunable circuit is responsive to said detected control tones for having its tuning changed to sequentially receive said control tones. |
