Sunday, September 11, 2022
Friday, September 16, 2022
Saturday, September 17, 2022
问题:一个管孔中布放2根以上子管时,其子管等效总外径不大于管孔内径的(...
Thursday, September 15, 2022
问题:长波、中波、短波都能借助于天空中电离层的折射和反射作用传播电磁波...
Sunday, September 11, 2022
问题:共用天线电视系统主要是解决技术上的()问题A、多副天线共同接收B、多用户分配C、多用户共用天线接收D、多用户共用一副天线接收...
Tuesday, January 10, 2023
问题:延长放大器与用户分配放大器的电路处理十分相似,但它的侧重是对()...
Thursday, September 15, 2022
Sunday, September 11, 2022
问题:前端机房内光传输设备的维护要点是:光传输设备应保证良好的工作环境...
Sunday, September 11, 2022
Thursday, September 15, 2022
问题:有源光设备的电光调制中若调制信号是视频信号,则可称为()。...
Thursday, September 15, 2022
Thursday, September 15, 2022
Friday, September 16, 2022
问题:为了减少反射波形成的重影,除了尽量做到阻抗匹配以减少反射波的强度...
Saturday, September 17, 2022
问题:邻频混合器的优点表现在()方面尤为突出A、插入损耗小B、相邻频道隔离度指标高C、输入路数多D、可以做成无源器件...
Wednesday, March 20, 2024
Friday, February 9, 2024
Thursday, September 15, 2022
问题:有线数字电视EPG系统包括日常工作所用到的EPG()和EPG导入...
Sunday, September 11, 2022
Saturday, September 17, 2022
问题:采用中频调制方式做电视频道调制器的最大好处是()...
Thursday, September 15, 2022