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一、概述随着民用住宅群的大量出现,CATV设计工作量也将大幅度增加,要求把CATV的设计与电力、通讯设计同时进行,一律采用暗装。但是CATV系统的天线竖立在住宅群楼顶上,而住宅群未建时,就无法测量接收点的场强,这是因为空间电磁波的传播受多种因素影响,估算结果与实际相差很大,CATV系统建成投产后使系统信噪比、终端电平等项指标达不到设计要求,尤其是在弱场强区,这个问题特别明显,从而给设计CATV系统带来较
I. Overview With the emergence of a large number of residential buildings, CATV design workload will also increase significantly, requiring CATV design and power, communications design at the same time, all using concealed. However, the antenna of CATV system is erected on the roof of residential buildings. When the residential buildings are not built, the field strength at the receiving point can not be measured. This is because the propagation of space electromagnetic waves is affected by many factors and the estimation results are greatly different from the actual ones. CATV system put into operation to make the system signal to noise ratio, terminal level and other indicators fail to meet the design requirements, especially in the weak field area, the problem is particularly evident, which gives the design CATV system to bring more