| 摘要 |
PURPOSE:To increase a locking range and to shorten a locking time by exercising AFC on a search basis and by performing rough tracking with a control channel signal higher in level than a pilot signal before precise AFC with the pilot signal. CONSTITUTION:A lincompex radio receiver which extracts a pilot signal contained in a transmitted signal and makes a reception frequency follow up a transmission frequency automatically is provided; when a control channel signal in a received output signal is not acquired by a BPF7, a discriminating circuit 14 outputs a signal 0 and when acquired, a signal 1 is outputted. With those signals, a sweep signal generation control circuit 15 is controlled to apply the output of a sweep signal generator 16 to a control input changeover circuit 17 and the output signal of a phase comparator 11 for AFC operation is searched for by the output of the discriminating circuit 14. Rough tracking is performed with the control channel signal higher in level than the pilot signal and then precise AFC control is exercised with the pilot signal, ths increasing a locking range and shortening a locking time. |
