| 摘要 |
PURPOSE:To simplify the circuit constitution by switching a deemphasis circuit and a splatter filter in interlocking with a press-to-talk switch and using them in common for a transmission section and reception section. CONSTITUTION:Analog switches 14, 15 are turned on in interlocking with the press-to-talk switch 6 during reception. Thus, a detection output from a FM demodulation output terminal 3 passes through a deemphasis circuit 10 and the splatter filter 11 and is outputted to a sound output terminal 4. On the other hand, the analog switches 12, 13 are turned on and the analog switches 14, 15 are turned off in interlocking with the press-to-talk switch 6 during transmission operation. As a result, a sound signal from a microphone 1 is subjected to frequency integrating (IDC operation) by the deemphasis circuit 10 via a pre-emphasis circuit 8 and a limiter amplifier 9, after harmonics are eliminated by the splatter filter 11, the result is outputted to an input terminal 2 of a PM modulator. |
