电视信号、声音信号和交互式服务用电缆网络.第4部分:同轴电缆网络用无源宽带设备(TA 5)

[中文适用范围]： IEC 60728的这一部分适用于系统插座、分路器和分接头、无源单端口或多端口设备，包括滤波器、衰减器、均衡器、电流隔离器、电源注入器、电缆接头、终端电阻和传输点，但不包括同轴电缆和接收器引线（见 5.2）。该标准涵盖了5 MHz 至3 000 MHz 的频率范围； • 确定某些参数的性能要求； • 规定了某些参数的数据发布要求； • 规定测量方法； • 引入定义质量等级的最低要求。除系统插座只有一级外，所有无源设备均分为三个等级。不同的网络需要相同的性能，在网络整合时，可以避免升级。实践经验表明，这三个等级满足了向用户提供最低信号质量所需的大部分技术要求。此分类不应被视为一项要求，而是为用户和制造商提供有关安装不同规模网络所需材料的最低质量标准的信息。系统运营商应选择适当的材料，以满足用户出口的最低信号质量并优化成本/性能，同时考虑网络规模和当地情况。所有要求和公布的数据应理解为在指定频率范围内和良好匹配条件下的保证值。 [外文原描述]： IEC 60728-4:2007 applies to system outlets, splitters and taps, passive single or multiple port equipment comprising filters, attenuators, equalizers, galvanic isolators, power injectors, cable splices, terminating resistors and transfer points, but excluding coaxial cables and receiver leads. This standard: - covers the frequency range 5 MHz to 3 000 MHz; - identifies performance requirements for certain parameters; - lays down data publication requirements for certain parameters; - stipulates methods of measurements; - introduces minimum requirements defining quality grades. This third edition cancels and replaces the second edition published in 2000, of which it constitutes a technical revision. It includes the following significant technical changes: Subclause 3.1 includes several new or modified definitions. Clause 4 includes added test methods for attenuation, isolation, through-loss, group delay variation, amplitude frequency response and two carrier intermodulation measurements for second- and third-order products. Clause 5 includes updated and new performance requirements.