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1.绪言甚高频(VHF)和特高频(UHF)下列车或汽车之类的移动无线电通讯,在隧道内,山谷里,地道内等无线电波难于传输的场合下,难以可靠地进行。为了解决这个问题,曾经探讨了各种天线以及开放型传输线。其中漏泄同轴电缆具有特性易于控制,特性稳定等优点,分一种很有效的方法。日立电线公司从1962年在日本国有铁道东海道新干线小田原试验段进行了漏泄同轴电缆的试验开始,对这种电缆一直进行着研制与制造,已经用在山阳新干线,以往线路的长隧道以及日立运输东京单轨公司,大阪市交通局的隧道内作为通讯传输线。
1. INTRODUCTION Mobile radios such as VHF and UHF vehicles or automobiles are difficult to reliably carry out when radio waves such as tunnels, valleys and tunnels are difficult to transmit. In order to solve this problem, various antennas and open transmission lines have been explored. One of the leaky coaxial cable has the characteristics of easy control, stable characteristics, etc., in a very effective way. Hitachi Cable Co., Ltd. started the experiment of leaked coaxial cables from the test section of Odawara of the Tokaido Shinkansen, Japan’s state-owned railway, in 1962. The cable has been developed and manufactured. It has been used in the long tunnels of the Sanyo Shinkansen and the old lines As well as the transmission lines from Hitachi Transportation Tokyo Monorail Co., Ltd. and Osaka City Transportation Bureau in the tunnel.