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About this Article
Written by: Andrew Schnickel
Written on: November 17th, 2000
Tags: entertainment, physics
Thumbnail by: Berserkerus/Wikimedia Commons
About the Author
In Fall 2000, Andrew Schnickel was a Junior majoring in CECS who enjoyed running barefoot in the rain.
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Volume III Issue II > Catch a Wave: Radio Waves and How They Work
Frequently used and often overlooked, the radio has played an important role in our lives and the lives of those before us. The mysteries of radio are abandoned because we simply expect wonderful sound to emanate from the speakers when the power is switched on. Seldom do we ponder the physics behind how the radio is able to deliver broadcast sound. Even more infrequently do we wonder what engineers have done to help us use and harness the power of radio waves. Exploring the phenomenon of radio waves will make you more aware of what occurs behind the scenes every time you tune that dial.

Introduction

TechnoBabble, Matthewcieplak/Wikim​edia Commons
Figure 1: Your favorite station - A TechnoBabble radio broadcast featuring Illumin. (Audio)
You are driving down the open road, not a care in the world. It's a sunny summer day and you have the car windows down. Everything seems almost perfect, yet something is missing. You turn on the radio, tune it to your favorite station (see Fig. 1), and instantly the car fills with sound. Suddenly, everything feels right. Radio is something most of us take for granted. Have you ever stopped to consider how a radio works? How does a radio know which station to play? What is AM, what is FM, and how are the two different? Why does FM sound better, but AM can be heard farther away? You have probably experienced a time when finding a particular radio station has been difficult. There are many factors involved in finding and receiving stations, factors such as modulation, broadcasting power, time of day, and geographical location. The key to getting the most out of your radio is to understand how radio works and how engineering has played a part in the development of a device which most of us use everyday.

Radio Basics

In order for you to hear your radio, a few things must happen. First, the radio station encodes some information on a radio wave. This is known as modulation. They then broadcast the radio wave with the encoded information onto a certain frequency. Your radio antenna picks up the broadcast based on the frequency to which your radio dial is tuned. Your radio then decodes the information from the radio wave and plays that information through the speakers as sound. So where does this information come from?