有线广播通常用架空钢线或音频电缆传送音频节目信号。传输线的固有衰减随着频率的升高而增大,其衰减特性如图1中的曲线①所示。当线路长度超过某一数值时,就会使系统的频响指标劣于标准的要求,这就要进行频响校正。为此,要设计一个衰减特性曲线(如图1②)与传输线的衰减特性曲 Cablecasts typically carry audio program signals over overhead wires or audio cables. The inherent attenuation of the transmission line increases with increasing frequency, and its attenuation characteristic is shown by the curve (1) in Figure 1. When the line length exceeds a certain value, it will make the system’s frequency response index worse than the standard requirements, which requires frequency response correction. To this end, to design an attenuation characteristic curve (Figure 1 ②) and the transmission line attenuation characteristics