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六十年代中期,我国的话音频载报机已从电子管式发展到晶体管式,各项性能指标亦有所提高.由于七十年代末期,为了改善通信质量和减少维护费用,国际电报电话咨询委员会建议(CCITT黄皮书R35),调频制话音频载报设备应符合方案B,即具有晶体控制的高稳定频率特性;同时考虑到自动转报中心存在用户租用电路和低速数据传输,需要有相应的载报机与之配套,因此我们将报路盘的模拟电路更新为数字电路.我们制成的一话四报插报机,频率分隔非均匀的三
In the mid-1960s, China’s audio-frequency signal reporting machine was developed from a tube-type to a transistor-based one with various performance indicators improved. Since the late seventies, in order to improve communication quality and reduce maintenance costs, the International Telegraph and Telephone Consultative Committee Recommendations (CCITT Yellow Book R35), FM audio equipment should be consistent with the program B, that is, with crystal control of high stability frequency characteristics; taking into account the automatic reporting center of the user leased circuits and low-speed data transmission, you need to have the corresponding The newspaper machine is matched with it, so we will update the circuit simulation circuit to a digital circuit.