Radio

At the radio station, the announcer speaks into a microphone.

The microphone changes the sound of his voice into an electrical signal.

This signal is weak and can't travel very far, so it's sent to a transmitter.

The transmitter mixes the signal with some strong radio signals called carrier waves.

These waves are then sent out through a special antenna at the speed of light!

They reach the antenna of your radio.

Your antenna "catches" the signal, and the radio's amplifier strengthens the signal and
sends it to the speakers.

The speakers vibrate, and your ears pick up the vibrations and
your brain translates them into the voice of the radio announcer back at the station.

When you consider all the places the announcer's voice travels.

Every radio station has its own frequency.

When you turn the tuning knob on your radio, you are choosing which
frequency you want your antenna to "catch."