| 摘要 |
A tone signaling system comprises a tone transmitter and a tone receiver in the form of an encoder and a decoder, respectively, for generating, transmitting and translating information in the form of a serial train of tone signals. The encoder utilizes a plurality of oscillators in the form of a bridged-T configuration for generating a plurality of selected frequencies under the control of a keyer and a plurality of timers which initiate tone generation and the spacing of the tones. The decoder employs a plurality of active tuned filter circuits, also in the same basic bridged-T configuration, which circuits and their following detectors are sequentially operated by the sequence of tones to effect energization of indicating apparatus.
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