manual frequency control

例句：

1. 1. The manual frequency control system allows for precise tuning of the radio's frequencyrange.
   手动频率控制系统允许对收音机的频率范围进行精确调谐。
2. 2. In this manual frequency control, the user can adjust the volume manually.
   在这个手动频率控制中，用户可以手动调整音量。
3. 3. The manual frequency control is crucial for maintaining the stability of the communication signal.
   手动频率控制对于保持通信信号的稳定性至关重要。