《电子制作》第二期刊登的李跃同志的《为普通彩电增加预选频道》一文中所介绍的方法,确实解决了普通彩电预选频道不够用的问题,但该方法中有十个频道采用循环选台,使用不太方便。所以,我认为如果不想使用节目监视功能的话,那么预选部分的电路可大大简化,具体方法如图所示。图中下半部分为新增的预选电位器,发光二极管用于指示哪一组预选器在工作(新增部分工作时会点亮),开关K用于对两组预选器的工作进行切换,二极管 The method described in “Making Preselected Channels for Ordinary Color TV” in Comrade Li Yue published in the second issue of “Electronics Production” really solved the problem of not enough regular color television preselected channels, but there are ten channels in the method that adopt the cycle Channel selection, not easy to use. So, I think if you do not want to use the program monitoring function, then the preselected part of the circuit can be greatly simplified, the specific method as shown. The lower half of the figure is the new preselected potentiometer, the LED is used to indicate which one of the preselector is working (the new part of the work will light), the switch K is used to switch the work of two preselector, diode