Origination
When a sound is first played, it is picked up by a microphone and translated into a sine wave that represents the sound. The carrier waves start out with no information inscribed in them until they are modified by the information from the electrical information from the microphone. These electromagnetic waves are more effective than mechanical waves, because electrical waves can travel in a vacuum while mechanical waves need a medium to travel in. Electromagnetic waves travel at the speed of light, which is faster than the mechanical waves that travel at the speed of sound.
Transmission
Radio transmission occurs when intelligence--sound or pictures--are transformed into sine waves and transmitted. Transmission can occur with amplitude modification (AM) or frequency modification (FM). Amplitude modification changes the size of the sine waves to represent the information and is most commonly used for transmitting AM radio stations and the image for televisions. Frequency modification alters the length of the sine waves to transfer information and is often used for FM radio stations and the sound of television stations. FM is preferable because it is resistant to static. The sine waves are broadcast by a radio tower. The more powerful the radio tower, the larger the area that the signal can be picked up.
Receiving a Transmission
To receive a radio transmission, you must have an antenna, tuner, detector, amplifier and speaker. When stations hit the antenna, they alter the magnetic fields and electric fields along the length of the antenna to transfer the electromagnetic wave into the receiving radio. The antenna will receive a multitude of different radio signals, so it is the tuner's job to select one frequency, or radio station, to focus on. The detector then translates the sine wave that the radio is picking up into sound, and the amplifier increases the sounds, which are then projected by the speaker.
Tags: sine waves, mechanical waves, information from, into sine, radio stations, radio tower
