| 摘要 |
PURPOSE:To compensate modulation degree without disturbing pre-emphasis characteristic, by separating a level adjusting circuit and a pre-emphasis circuit. CONSTITUTION:An audio input signal given to an input terminal 20 is inputted to a level adjusting circuit 22 for level adjustment. The input signal with level adjustment is applied to a non-inverting terminal of an amplifier 30 via a coupling capacitor 28. The amplifier 30 is provided with a feedback circuit 32 which negatively feeds back the amplified output to the input side and the feedback circuit 32 is provided with a pre-emphases circuit 34. The amplified output of the amplifier 30 provided with the pre-emphasis characteristics at the circuit 34 is applied to an FM modulation circuit 42 for FM modulation. |
