| 摘要 |
PURPOSE:To attain an accurate tuning operation in a short time, by widening an IF band at coarse adjustment and narrowering it at fine adjustment. CONSTITUTION:In the case of the coarse adjustment, a code generator 17 changes a programmable frequency divider 16 in 10 increments. In this case, a referece oscillator 15 supplies a signal of 10kHz to a phase comparator 14. Further, the band of an intermediate frequency is made broad. A PLL circuit outputs a signal in 10kHz step and a receiver sweeps the band in 10kHz step. Since stations within a prescribed range of crosstalk are received at the same time by widening the band, an objective station is found out quickly. In the case of the fine adjustment, the PLL circuit outputs a signal in 1kHz step and the band is also narrowered. Thus, the minute adjustment is done easily. |
