论文部分内容阅读
在远离电视台的边远地区收看电视节目时,电视机的屏幕上会出现许多雪花点,而且噪声很大,这并不是什么故障,主要是电视接收机距离电视台远、信号太弱的缘故。本文介绍的简易电视天线放大器,在远距离接收时仍能获得良好的接收效果,它具有电路简单、调试简便等优点,适用于VHF的1～12频道。电路如图1所示。该放大器由BG_1和BG_2组成两管直耦式放大电路,这种电路具有较高的增益,采用这种直接耦合对作为交流放大器的好处在于节省元件、频响特性好,由于在这种电路中采用了一些负反馈,所以工作点比较稳定。电视信号经外接天线经电
When watching TV programs in remote areas far away from the TV stations, many snowflakes appear on the screen of the TV and there is noisy noise. The main reason is that the television receiver is far away from the TV station and the signal is too weak. This article describes the simple TV antenna amplifier can still receive good results when receiving long distances, it has the advantages of simple circuit, easy commissioning, suitable for VHF channel 1-12. Circuit shown in Figure 1. The amplifier consists of BG_1 and BG_2 composed of two direct-coupled amplifier circuit, this circuit has a high gain, the use of this direct coupling as the AC amplifier has the advantage of saving components, good frequency response, as in this circuit Using some negative feedback, so the work point is relatively stable. TV signal via an external antenna via electricity