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模拟音频广播的现状及其发展 模拟音频广播(AAB)分为调频广播和调幅广播两类。调频立体声广播发射机已实现全固态化,音质好,很受广大听众的欢迎。 中短波模拟调幅广播始于二十世纪30年代,乙类板调一直居主导地位。50年代出现了自动板调。到了80年代,先后出现了几种先进的调制方式:脉冲宽度调制PDM(Pulse Duration Modulation)、脉冲阶梯调制PSM(Pulse
The status of analog audio broadcasting and its development Analog audio broadcasting (AAB) is divided into FM radio and AM two types. FM stereo radio transmitter has achieved full solid state, sound quality, very popular with the majority of listeners. Medium and shortwave analog AM broadcasting began in the 1930s, Class B board has been dominant. In the 1950s there was an automatic tone. By the 1980s, there have been several advanced modulation methods: Pulse Duration Modulation (PDM), Pulse Pulse Modulation (PSM)