pulse coding tube

例句：

1. 1. This pulse coded tube is used to transmit signals over long distances.
   这种脉冲编码管用于在长距离内传输信号。
2. 2. The engineers developed a new type of pulse coded tube for better communication.
   工程师们开发了一种新型的脉冲编码管，以改善通信。
3. 3. The pulse coded tube was the first device to transmit audio signals over telephone lines.
   脉冲编码管是第一个通过电话线传输音频信号的设备。