The preliminary pulse serves only AGC purposes and may be ignored by the receiving software. 初步脉冲只能自动增益控制宗旨和可能会被忽略的接收软件。
The second down-conversion mixer circuit is achieved by function chips, including the high-IF amplifier, the second mixer and the AGC amplifier, etc. 二次混频主要采用选择功能芯片的方式实现，包括高中频放大器，第二混频器，自动增益控制放大器等。
