"超外差收音机原理解析：工作原理、电路图及优劣比较。"

超外差收音机是一种采用超外差原理的无线电接收设备，其工作原理及部分电路图被详细介绍在一个幻灯片课件中。该课件首先介绍了直放式收音机的特点，指出其电路简单、易于安装调试和成本低，但灵敏度低、选择性不太好的缺点。为了克服这些不足，引入了“超外差”概念。超外差式收音机的工作原理便是通过输入信号和本机振荡信号产生一个固定中频信号，从而实现信号的处理和解调。通过超外差的过程，将高频信号转换为中频信号，使得接收信号更加稳定和可靠。在课件中还展示了典型的单管直放式收音机电路示例和超外差收音机方框图，详细说明了各个部分的功能和连接方式。通过使用同轴来实现同步，保证了信号的传输和处理的稳定性。整个课件通过简洁清晰的内容和图示，让学习者更加深入地了解了超外差收音机的原理和实现方式。 Superheterodyne receiver principle slide courseware; Superheterodyne receiver principle slide courseware, the content in the courseware describes the working principle of the superheterodyne receiver and some circuit diagrams; working principle of the superheterodyne receiver working principle of the superheterodyne receiver Electronic Association November 19, 2005 Features of direct push receiver Features of direct push receiver The circuit is simple, usually only uses 1-4 transistors and some basic components. Easy to install and debug, low cost, but its sensitivity is low, and selectivity is not very good. To overcome the above shortcomings, we introduce the concept of "superheterodyne". Please first look at the block diagram of the superheterodyne receiver. Typical single-tube direct push receiver circuit example Typical single-tube direct push receiver circuit example Superheterodyne receiver block diagram Superheterodyne receiver block diagram Low frequency variable frequency detection power amplifier tuning local oscillation intermediate frequency medium power supply AGCYTX heterodyne heterodyne super 525-1605 L1C1L2C2L3C3L4C4 use coaxial to achieve synchronization fsfLfIfL-fs = fI Super super heterodyne heterodyne external difference: the process of generating intermediate frequency signal by input signal and local oscillating signal. Super heterodyne: the process of generating a fixed intermediate frequency signal by input signal and local oscillating signal. Because it is lower than high frequency signal and higher than low frequency signal;".