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五、电视广播及其设备(三续)(二)电视广播发射台设备电视广播发射台的任务是把电视节目的图象信号和伴音信号用无线电波的形式发射出去,它的主要技术设备有图象发射机、伴音发射机和天线系统.由于图象信号频带较宽,因此图象发射机和伴音发射机的载频都在超高频范围之内.我国电视制度规定,伴音载频比图象载频高出6.5兆赫,图象信号采用调幅制,而伴音信号则采用调频制.图象发射机的峰值功率与伴音发射机的载波功率的比值世界各国有所不同,一
V. TV BROADCAST AND ITS EQUIPMENT (III) (II) TV BROADCAST TRANSMISSION EQUIPMENT Equipment The task of a television broadcasting transmitting station is to transmit the image signals and accompanying signals of television programs in the form of radio waves. The main technical equipment there is Image transmitter, sound transmitter and antenna system.As the wideband video signal, so the image transmitter and sound transmitter carrier frequency are in the ultra-high frequency range.China’s television system provides that the sound carrier frequency ratio Image carrier frequency higher than 6.5 MHz, the image signal using AM system, and audio signals are used FM system.Power of the image transmitter and the sound power transmitter carrier power ratio in different countries in the world, a