| 摘要 |
PURPOSE:To put a visual sensing means in operation at an optional level by varying the flashing level of a display device by a level regulator independent of a squelch regulator which varies the opeing/closing level of a squelch circuit. CONSTITUTION:A squelch signal corresponding to the input level of a receive signal from a reception part 2 is extracted and passed through the squelch regulator 3, and the signal is amplified by a DC amplifier 4 to control the opening and closing of a squelch gate 5. The output of the gate 5 is passed through a volume regulator 6 and amplified by a low frequency amplifier 7 to output a receive sound from a speaker 8. When the receive signal is lower than a level set by the regulator 3, the gate 5 is closed to inhibit the receive sound from being outputted from a speaker 10. Further, the squelch signal from the reception part 2 is passed through the level regulator 11 and then amplified by a DC amplifier 12 to turn on the display device 10 through a driver 9. Therefore, the receive signal is only set by a regulator 11 below the level set by the regulator 3 to detect such a weak input signal that the gate 5 is not opened being sensed from the lighting of the display device 10. |
