论文部分内容阅读
自本刊今年第六期发表“收音机二次变频电路”以后,读者方民华、杨生道、周良君、周必文、陈一民、金国寿、刘?娟、陈金根、孙亦铃、尤振国、周日麟、?丹仑、朱越南等同志纷纷来信表示意见,这些意见主要是:1.输入回路似有缺点,尤其在短波段将有严重象频干扰,因此短波段的收音效果将大受影响.2.第一变频级本地振荡频率高于信号频率,将使短波段电台在刻度盘上位置高低反置.3.第二变频采用负阻振荡似有问题(因第三栅无直流偏压电阻).4.L_1～L_9缺乏具体制作数据,难于仿制.
Since the publication of the sixth issue of this year, Radio Frequency Rewinding Circuits, readers Fang Minhua, Yang Shengdao, Zhou Liangjun, Zhou Biwen, Chen Yimin, Jin Guoshou, Liu Juan, Chen Jingen, Sun Yiling, You Zhenguo, Zhu Vietnam and other comrades have letters to express their views, these views are mainly: 1. The input circuit seems to have shortcomings, especially in the short-band will have serious image-frequency interference, the short-wave radio effect will be greatly affected .2 The first inverter level The local oscillation frequency is higher than the signal frequency, which will cause the short-band radio station to invert the position on the dial. (3) The second inverter uses the problem of negative resistance oscillation (because the third grid has no DC bias resistor) L_9 lack of specific production data, difficult to imitate.