| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time needed for a search by sequentially searching for a predetermined broadcast frequency, correcting the tuning frequency and starting receiving a broadcast when the frequency error of the received broadcast wave is within a detection range, and closely searching a digital sound broadcast frequency band at narrow frequency intervals and searching for the center frequency when not. SOLUTION: A controller sets a reception frequency to the lowerlimit frequency of a frequency grid first (90). Then it is decided whether the output of a level detector is larger than a specific value (102) to decide whether or not there is a broadcast wave in the current reception frequency band. When there is a broadcast wave, it is decided whether it is a sound broadcast signal (103). When it is decided that the wave is not the digital sound broadcast signal (103), the reception frequency is set to a frequency right above in the frequency grid (91). Thus, a search in the broadcast band is repeated if a digital sound broadcast signal can not be detected. |
