标准摘要
[中文适用范围]： 通过参考第 1 部分中包含的各种条款和子条款来补充 IEC 457-1，其中添加了重要信息。这涉及最大频率、电气长度、临时型号、标准大气条件 [外文原描述]： Describes the mechanical, electrical and environmental specifications of the 21 mm pecision connector, the reflection coefficient and attenuation of which have to be measured up to 6 GHz.
英文名称Rigid precision coaxial and their associated precision connectors. Part 4: 21 mm rigid precision coaxial line and associated hermaphroditic precision coaxial connector - Characteristic impedance 50 ohms (Type 9/21) - Characteristic impedance 75 ohms (Type 6/21)