本文介绍传输功率高达500kW、高频广播用大尺寸(外径254mm)同轴电缆的设计过程.这种新型传输线是半柔软的,以法兰连接段的长度生产,以标准的12.2m装运长度封装和运输.我们进行了初步的电气性能、热性能和结构分析,制作了试样并进行了测试.还在这种新型传输线的生产长度上完成了电气性能、机械性能和热性能的测试,对测试结果作了介绍.最后简单说明了敷设和维修方法. This article describes the design of a large coaxial cable with a transmission capacity up to 500 kW and a large size (254 mm OD) for high frequency broadcasting. The new transmission line is semi-flexible and is produced with the length of the flange connection, with a standard shipping length of 12.2 m Packaging and shipping We performed preliminary electrical, thermal and structural analyzes, fabricated samples and tested them, completed electrical, mechanical and thermal performance tests on the production length of this new transmission line, The test results are introduced.Finally, a brief description of the laying and maintenance methods.