| 摘要 |
PROBLEM TO BE SOLVED: To correctly seek an ensemble band. SOLUTION: When the reception frequency of a front end 2 is tuned by a plurality of ensembles, and a NULL detection circuit 20 detects a NULL symbol detection signal with a reception frequency, a system controller 37A checks whether or not a transmission mode allowed at an ensemble band of a seek object this time is detected by the NULL detection circuit 20 and stops seeking when detected and allows an automatic frequency adjustment system, consisting of a frequency error detection circuit 33A, an integration circuit 34, a D/A converter 35, a reference signal oscillator 13, and PLL circuits 7, 12, 17 for adjusting the frequency, but continues seeking when no transmission mode which is not allowed in the ensemble band of a seek object this time is detected. |
