| 摘要 |
PURPOSE:To facilitate receiving road-side information by depressing a service request button provided in a car radio of the system, where digital quantities for tuning are stored and channels are selected with push buttons, to receive roadside information. CONSTITUTION:Digital quantities corresponding to tuning frequencies are stored in the electronic car radio. When a desired button on a key matrix KMX connected to a control part CONT is depressed to select a channel, a local oscillator LO is controlled by a PLL so that a local oscillated frequency for one wave of FM or AM is generated. A button which selects 1,620kHz frequency for roadside traffic information service is added to channel selecting buttons. The broadcast which is received just before depression of this button is received again a prescribed time after depression of this button or by the operation of a return button. If this button is depressed continuously, the receiving frequency is switched to stand-by frequency 1,629kHz. In this case, the original broadcast is received after a prescribed time. Thus, road side traffic information repeated in a short time is received easily.
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