| 摘要 |
PURPOSE:To stabilize the reception condition under driving, by automatically correcting the tuning shift produced due to state of electromagnetic waves. CONSTITUTION:The PLL4 inputs the oscillation frequency from the local oscillation section 1e or 2e in the radio receiver, compares it with the tuning frequency and transfers the tuning voltage VCO to the tuning varactor diode 1k or 2k so that the same value can be obtained, to lock with the tuning to the frequency set to the PLL4. The microcomputer 3 decides if the intensity of electromagnetic waves at the frequency increased or decreased by DELTAf for channel space's share to the frequency (f) tuned at present is more than a given value, and the operation processing for tuning can be executed at the frequency with optimum reception state. |
