“随身听”袖珍收放机具有体积小、音质优美动听等特点而成为众多音乐爱好者的宠物。然而,这类机子的调频收音往往有灵敏度不够高、选择性不够好的缺点。因此很有必要做如下的“打摩”。一、增加一级高频放大。随身听一般都是用耳机拖线作为调频收音的天线,这样做会造成接收到的信号不稳定,和灵敏度低。而增加一级高频放大可对天线信号放大改善灵敏低的缺点。其电路如图1所示。 “Walkman” Pocket Recipient has the characteristics of small size, beautiful sound and beautiful and become a music lover of many pets. However, the FM radio of this kind of machine often has the shortcoming of not high sensitivity and poor selectivity. Therefore, it is necessary to do the following “massage.” First, increase a high-frequency amplification. Walkman is generally used as a drag-and-drop earphone FM radio antenna, doing so will cause the received signal is unstable, and the sensitivity is low. The increase of a high-frequency amplification of the antenna signal amplification to improve the sensitivity of the shortcomings. The circuit shown in Figure 1.