A FEW FACTS ABOUT RADIO STATIONS

Just about everyone listens to the radio! 99% of homes in the United States have a least one radio. Most families have several radios. How many do you have? Don't forget to count the radio in your car!

What goes on at your favorite radio station? Ever wondered?

Sound is sent from the radio station through the air to your radio by means of electromagnetic waves. News, music, Bible teaching, baseball games, plays, advertisements- these sounds are all converted into electomagnetic waves (radio waves) before they reach your radio and your ears. How is this done?

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 amplifiers strenghten 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, isn't it amazing how clearly you can hear radio programs?

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."

There are two kinds of radio stations: AM and FM. That's why there are two dials on your radio. AM is used mostly for stations that specialize in talking, such as Christian stations that have Bible stories and sermons; sports stations that broadcast live baseball and football games; and stations that specialize in news programs and "talk shows," where listeners call the station and discuss various topics. FM is used mostly for stations that specialize in music.

For a more detailed explanation of how radio stations work, you can visit Science Odyssey's web site. To make the Radio Transmission Activity work, you will need a program on your computer called Shockwave. Please get your parents' help with this!!!