| 摘要 |
PURPOSE:To enable effective operation to the failure in audio signal, by constituting unifiedly the audio de-emphasis circuit and the dropout erase section. CONSTITUTION:The electronic control switch 12 is open when the failure output pulse 11 of the input FM signal is at high potential and closed at low potential. Further, the resistor 13 and the capacitor 14 constitute the de-emphasis circuit and the time constant is selected, for example, as 75mu sec in signal formation. When the demodulated audio signal 6 including failures is simply de-emphasized, although the effect of failure is left in the form of integration more or less, the failures in the audio output signal 8 can completely be rejected by operating the dropout erase section with the switch 12. It is best to constitute unifiedly for the dropout erase section and the de-emphasis section. |
