The sounds and images are converted into electrical signals by a microphone( sounds) or video camera( images), amplified, and used to modulate a carrier wave that has been generated by an oscillator circuit in a transmitter.

• 声音合图像由话筒(音)摄像机(像)换为电子信号，经过放大后，用来调制发射器中一个振荡器产生的负载电波。