Radio stations began selling “air time” as a way to pay their workers and to pay for needed equipment. A few minutes of air time were sold to different companies so they could tell about their products to the radio station’s listeners. This method of supporting radio and later television is still used today.
SHIRLEY GRIFFITH: Radio changed the way people thought and lived. It permitted almost everyone to hear news about important events at the same time. Political candidates could be heard by millions of listeners. The same songs were heard across the country.
The work by British scientist James Maxwell and German scientist Heinrich Hertz led to the development of modern communications technology. This includes television broadcasts, satellite use, cellular telephones, radio-controlled toys and much more.
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STEVE EMBER: Now we will explain electromagnetic waves. We will begin with Heinrich Hertz’s experiment. You can also try this experiment. First, move the controls on your radio to an area where no station is being received.
Now, you will need a common nine-volt battery and a metal piece of money. Hold the battery near the radio and hit the top of the battery with the coin. You should hear a clicking noise on the radio.
Your coin and battery are a very simple radio transmitter. This radio will not transmit very far. However, if you know a little of Morse code, you could communicate with this device.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25