tuner input circuit

例句：

1. 1. The tuning fork is used to tune the radio frequency.
   用这个调音叉来调频收音机。
2. 2. The input circuit of the receiver is crucial for receiving signals.
   接收机的输入电路对于接收信号至关重要。
3. 3. The engineer carefully checked the input circuit to ensure it was working properly.
   工程师仔细检查了输入电路，确保它正常工作。