本文介绍的这种短波—中波变换器能将短波电台的频率变换到中波频率上,供只有中波段的收音机接收。该变换器具有灵敏度高、使用方便、制作容易、成本低廉的特点。工作原理该变换器的电原理图如图1所示。它由变频和差频放大两部分组成。由晶体三极管V1、振荡线圈T、电容器C3等组成一个共基调发、 The shortwave-to-medium wave converter introduced in this paper can convert the frequency of a shortwave radio to a mid-wave frequency for reception by only the mid-band radio. The converter has high sensitivity, easy to use, easy to manufacture, low cost features. The working principle of the converter’s electrical schematic shown in Figure 1. It consists of frequency and difference amplification two parts. By the transistor transistor V1, oscillation coil T, capacitor C3 and so on to form a common base hair,