| 摘要 |
PURPOSE:To prevent the mixing of noises to a service signal even if on/off of a pilot detector is repeated by inserting a filter passing DC power from a power supply to the pilot detecting part and interrupting a signal having a part of the frequency band of the service signal between the pilot detecting part and the power supply. CONSTITUTION:An input signal is converted into an intermediate frequency signal, demodulated to a base band signal by an FM demodulator through an intermediate frequency filter and a limiter amplifier and then amplified by a base band amplifier 7. The base band amplifier 7 and the pilot detector 8 are connected to a common DC power supply through a power supply line 13, but the low-pass filter 17 passing DC and interrupting the frequency band of a service signal is inserted into a power supply line on the pilot detector 8 side. Even if repeating frequency due to noise is generated in the pilot detector 8, the frequency is interrupted by the filter 17 and prevented from the leakage to other circuits through the power supply line 13, so that the noise is not applied to the service signal. |
