论文部分内容阅读
由于在十九世纪70年代后期电话的应用,作为长距离通信主要手段的电报电路在1900年后开始让位.最初,音频传输所提出的问题较少,因为只涉及短距离.然而,到1896年,利用架空铜线传输的长途系统已经出现,其标准规格为干线电路每英里800磅,较短电路每英里400磅.它们必然因坏天气的破坏而使特性受损害.解决这一问题,最终是采用地下电缆作为长途网络的标准设施,但是在其他电阻及电容值比架空电缆高的问题没有解决之前是不可能的.解决这个问题主要依靠加感、平衡、放大和均衡等技术加以解决.音频传输的历史
Due to the use of telephony in the late 1970s, the telegraph circuit, which was the primary means of long-range communications, began to give way after 1900. Initially, audio transmission posed fewer problems because it involved only short distances. However, by 1896 Long-haul systems using overhead copper lines have emerged in the year, with standard specifications of 800 pounds per mile for trunk circuits and 400 pounds per mile for shorter circuits, which are bound to compromise features due to bad weather damage.To solve this problem, Ultimately, underground cables are used as a standard facility for long distance networks, but it is not possible until other problems such as higher resistance and capacitance than overhead cables can not be solved.This problem is mainly solved by techniques such as sensing, balancing, amplification and equalization The history of audio transmission