| 摘要 |
<p>An FM/AM switch (31) selects an FM detected signal or an AM detected signal. A capacitor (4) is provided to eliminate dc components from the FM detected signal. A low-cut frequency switch (33) selects a resistor, specified by a control signal, from resistors (Ra-Rc). A high pass filter is composed of the capacitor (4) and the resistor selected by the low-cut frequency switch (33). The low frequency components of the AM detected signal are attenuated by this high pass filter. The cutoff frequency of this high pass filter is adjusted by the selection of resistors.</p> |
