Receivable frequencies based on a predetermined instruction signal are scanned in a first direction and across a frequency range extending from a first start frequency to a first end frequency. The tuning is retraced to the first start frequency, and scanning is resumed in the opposite direction across a second frequency range extending from the first start frequency to a second end frequency. Next, tuning is retraced to the second start frequency and scanning is resumed in the first direction across a third frequency range extending from the first end frequency to a third end frequency. The scan operation is repeated until predetermined upper and lower frequency limits are reached. When one of the frequency limits are reached, scanning is performed for one or more frequency ranges in the opposite direction without retrace until the second frequency limit is reached.