一、引言我国电信,目前主要是利用架空明线来传输的。随着社会主义建设的不断发展,电信线路除在特别繁忙的路线上将逐步改用电缆外,广大地区今后仍将在原有明线基础上不断地扩展并增加囘路数和提高传输频率。为了保证电信的畅通,就必须要求明线设备在建筑安装上 First, the introduction of China’s telecommunications, the current main is the use of overhead lines to transmit. With the continuous development of socialist construction, the telecommunications lines will be gradually replaced by cables on a particularly busy route. The vast majority of regions will continue to expand and increase the number of circuits and the frequency of transmission on the basis of the original clear lines in the future. In order to ensure the smooth flow of telecommunications, it must require open-line equipment in the building installation