画中画彩电“天线分配器”故障检修二例

• 作 者: 刘德智
• 出 处: 家电检修技术
• 发表日期: 2002年12期
• 关键词: 故障检修 高频头 画中画 输出电路 选台 射频输入 电感线圈 极电压 时可 电源端

画中画彩电有两个高频头,分别用于主、副通道选台,为了使两个高频头共用一个天线输入端,画中画彩电多采用天线有源二分配器,将从天线输入的射频信号一分为二,分别加到主、副画面高频头的射频输入端,由于分配器内两路信号输出电路完全相同,检修时可将分配器输出的两路信号对调接入主、副画面高频头,也可直接将天线输入的射频信号送入主、副画面高频头测试,根据主、副画面图像异常情况便可确定分配

PIP color TV has two high-frequency head, respectively, for the main channel and channel selection, in order to make the two tuners share an antenna input, picture-in-picture multi-use antenna active two splitter, the antenna The input RF signal is divided into two, respectively, added to the main and sub-picture RF tuner input terminal, the distributor of the two signal output circuit is identical, overhaul can be splitter output of the two-way signal access The main and sub-picture of the high-frequency head, the antenna can also be directly input RF signal into the main and sub-picture tuner test, according to the main and sub-picture abnormalities can determine the distribution