How does a radio work?
A radio changes the radio waves sent out by a broadcasting station back into sound waves that we can hear.
When you listen to a radio, you may wonder how the sounds get to your radio from the broadcasting station.
The answer is that your radio picked up the sounds in the form of radio waves.
You can’t see or hear radio waves, but they move through the air around you all the time.
At a broadcasting station a microphone changes the ordinary sound waves of voices or music into electrical signals.
A transmitter, or sender, changes the electrical signals into radio waves and sends them out into the air in all directions from a tall, broadcasting antenna.
When radio waves strike the antenna inside your radio, the antenna turns the radio waves back into weak electrical signals again. The radio makes these weak signals much stronger.
Finally, the loudspeaker changes the electrical signals back into sound waves, and you hear a copy of the sounds made at the broadcasting station. – Dick Rogers