| 摘要 |
PURPOSE:To check a PCM system with high accuracy in a simple way by using a circuit which supplies the signals of a tape head system to a data strobe circuit with no intervention of an equivalent circuit. CONSTITUTION:In a reproduction mode a PCM processor 3 detects signals and corrects their errors via a reproduction head 6, a preamplifier 7, an equivalent circuit 9, a changeover switch 8 for input terminal 10 for recording PCM signal of another base board and a data strobe 11. Then the digital signal is demodulated by a D/A converter and delivered to a voice output terminal 13. If the signal of a tape head system is used when a reproducing circuit for PCM signal is checked, a long period of time is needed for decision of the propriety of a PCM system. Therefore the recording PCM signal given from another base board is supplied to the terminal 10. Then the input and switching of this PCM signal is carried out by the switch 8. In such a way, the reproducing circuit for PCM signal can be checked quickly and accurately.
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