七管超外差调幅收音机li.

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

Seven tube specialized superheterodyne an am radio

Author: Yong Ming Li

Autor: Bai Xiao Lei

abstract

In life, everywhere we work with wireless communication, such as wifi, now TV is closely related to wireless communications, and wireless communication is mainly composed of transmitting and receiving devices. Which two of the most widely used way to send and receive is frequency modulation and amplitude modulation, frequency modulation way along with the social development will become the main way of working of modern equipment.

Superheterodyne radio, from a weak high-frequency antenna received signals v1 first level after level 1 or several high frequency small signal amplifier amplification for v2. Then sent to the mixer and the local oscillator continuous oscillation voltage generated by the mixed v3, v4 output voltage generated by envelope shape remains unchanged, still with the original signal waveform is similar, but the carrier frequency is changed for v2 and v3 of the difference of the two high frequency (or close). This is called intermediate frequency. Intermediate frequency voltage v4 after intermediate frequency amplifier v5, send one detector, detector output voltage v6. Finally v6 in intermediate frequency amplifier amplification process for v7, sent to the speakers converted into sound signal.

Specialized superheterodyne receivers can greatly improve the receiver of the gain, sensitive and selective.

key words : Specialized superheterodyne, welding, commissioning, FM

目录

1 实训目的 (1)

2 工作原理 (2)

3 实训内容 (4)

3.1实习器材 (4)

3.2 元件说明 (4)

3.3安装顺序 (4)

3.4收音机的组装 (5)

3.5收音机的调试 (5)

3.5.1调幅（AM）部分 (5)

3.5.2调频（FM）部分 (5)

4注意事项 (7)

4.1 焊接的热量和焊接的时间 (7)

4.2焊接过程的把握 (7)

5总结 (8)

致谢 (9)

参考文献...................................................................................... 错误！未定义书签。附录 (10)

1 实训目的

掌握常用电子器件的类别、型号、规格、性能及其使用范围，能查阅有关的电子器件图书；能够正确识别和选用常用的电子器件，并且能够熟练使用万用表；学习并掌握超外差收音机的工作原理；熟悉手工焊锡的常用工具的使用及其维护与修理，基本掌握手工电烙铁的焊接技术；学会调试收音机，能够清晰的收到电台；了解电子产品的焊接、调试与维修方法。初步学习调试电子产品的方法，提高动手能力。