To the shipboard radio operators, it was a miracle -- a Christmas miracle. Instead of hearing the usual dots and dashes of Morse Code, these listeners heard an eerie Silent Night, played by a violin. It was Christmas Eve, 1906, and this broadcast was ...
FM radio works the same way that AM radio works. The difference is in how the carrier wave is modulated, or altered. With AM radio, the amplitude, or overall strength, of the signal is varied to incorporate the sound information. With FM, the frequenc...
1971年的10月，北京无线电厂接到了北京市关于在北京饭店及主要星级饭店配备国产高级半导体收音机的任务。那一年，乒乓外交使中美关系迅速解冻，联合国恢复了我国的合法席位。
为...
OK. So we have a signal that is sent to a radiosmitter's antenna. How does that signal get from the antenna to the air?
Let's first take a look at the signal. The signal is an electic current, and every electric current is actually electrons mo...
