学校代码10126学号01161059本科学年论文题目超外差式七管调幅收音机院系内蒙古大学鄂尔多斯学院专业名称电子信息科学与技术年级2011级学生姓名李永明指导教师白晓磊2013年07月16日七管超外差调幅收音机摘要在生活中，我们无处不在的与无线通信打交道，例如现在用的wifi，电视都是与无线通信紧密相关的，而无线通信主要由发射和接收设备组成。目前应用最广的两种发送接收方式是调频与调幅，随着社会发展调频方式将成为现代设备的主要的工作方式。超外差式收音机，是从天线收到的微弱高频信号v1先经过一级或几级高频小信号放大器放大为v2.然后送至混频器与本地振荡器所产生的等幅振荡电压v3相混合，所得到的输出电压v4包络线形状不变，仍与原来的信号波形相似，但载波频率则换为v2与v3两个高频频率之差（或合）。这叫中频。中频电压v4在经过中频放大器v5，送人检波器，得检波输出电压v6。最后v6在经过中频放大器放大为v7，送到扬声器中转变为声音信号。超外差式接收机能够大大提高接收机的增益、灵敏度和选择性。关键词：超外差，焊接，调试，调频SeventubespecializedsuperheterodyneanamradioAuthor:YongMingLiAutor:BaiXiaoLeiabstractInlife,everywhereweworkwithwirelesscommunication,suchaswifi,nowTViscloselyrelatedtowirelesscommunications,andwirelesscommunicationismainlycomposedoftransmittingandreceivingdevices.Whichtwoofthemostwidelyusedwaytosendandreceiveisfrequencymodulationandamplitudemodulation,frequencymodulationwayalongwiththesocialdevelopmentwillbecomethemainwayofworkingofmodernequipment.Superheterodyneradio,fromaweakhigh-frequencyantennareceivedsignalsv1firstlevelafterlevel1orseveralhighfrequencysmallsignalamplifieramplificationforv2.Thensenttothemixerandthelocaloscillatorcontinuousoscillationvoltagegeneratedbythemixedv3,v4outputvoltagegeneratedbyenvelopeshaperemainsunchanged,stillwiththeoriginalsignalwaveformissimilar,butthecarrierfrequencyischangedforv2andv3ofthedifferenceofthetwohighfrequency(orclose).Thisiscalledintermediatefrequency.Intermediatefrequencyvoltagev4afterintermediatefrequencyamplifierv5,sendonedetector,detectoroutputvoltagev6.Finallyv6inintermediatefrequencyamplifieramplificationprocessforv7,senttothespeakersconvertedintosoundsignal.Specializedsuperheterodynereceiverscangreatlyimprovethereceiverofthegain,sensitiveandselective.keywords:Specializedsuperheterodyne,welding,commissioning,FM目录1实训目的....................................................................................................................12工作原理....................................................................................................................23实训内容....................................................................................................................43.1实习器材..........................................................................................................43.2元件说明.........................................................................................................43.3安装顺序..........................................................................................................43.4收音机的组装..................................................................................................53.5收音机的调试..................................................................................................53.5.1调幅（AM）部分..................................................................................53.5.2调频（FM）部分......................................................................................
