squelch opening level and closing level是什么意思

用法例句

To drivers convenience, the DCS technology of mobile radio transceivers is introdued with PC, channel parameter programming and signaling code programming, it is simple and straight-forward and is of low production costs.

为了司机操作方便，在车用通信机中引入数码静噪系统；用ＩＢＭＰＣ对通信机信道参数及信令码进行编程，操作方法简单明了，且大幅度降低生产成本；用锁相环压控振荡器输出电压Ｕｃ对本振频率带宽跟踪补偿，可使带宽增加０。