| 摘要 |
PURPOSE:To prevent the S/N deterioration of an output signal, by turning on and off a switch that gives connection or disconnection to the received signal of a receiver and is provided to each receiver by means of the squelch signal supplied from the receiver. CONSTITUTION:The output of receivers 1 and 2 are fed to a demodulator 3 via analog switches 6 and 8 plus an analog adder 10. The squelch signals of the receivers 1 and 2 are fed to an FF13 and an FF15, and the outputs of the FF13 and FF15 turn on and off the swiches 6 and 9. When the receiver 1 receives electromagnetic waves, the output Q of the FF13 is set at a high level to close the switch 6. In this case, a one-shot circuit 18 resets the FF15 to open the switch 8. When both receivers 1 and 2 receive electromagnetic waves at one time, only the signal of the terminal 5 is delivered to a terminal 11. In case one of the two receivers has a trouble, the squelch signal has no change. Thus the output of the faulty receiver is never delivered to the terminal 11. |
