Radio

Radio: Making Waves in America

Radio-wave technology is one of the most important technologies used by man. It has forever changed the United States and the world, and will continue to do so in the future. Radio has been a communications medium, a recreational device, and many other things to us. When British physicist James Clerk Maxwell published his theory of electromagnetic waves in 1873, he probably never could have envisioned the sorts of things that would come of such a principle. His theory mainly had to do with light waves, but fifteen years later, a German physicist named Heinrich Hertz was able to electrically generate MaxwellÕs ÒraysÓ in his lab. The discovery of these amazing properties, the later invention of a working wireless radio, and the resulting technology have been instrumental to AmericaÕs move into the Information Age. The invention of radio is commonly credited to Guglielmo Marconi, who, starting in 1895, developed the first ÒwirelessÓ radio transmitter and receiver. Working at home with no support from his father, but plenty from his mother, Marconi improved upon the experiments and equipment of Hertz and others working on radio transmission. He created a better radio wave detector or cohere and connected it to an early type of antenna. With the help of his brothers and some of the neighborhood boys he was able to send wireless telegraph messages over short distances. By 1899 he had established a wireless communications link between England and France that had the ability to operate under any weather conditions. He had sent trans-Atlantic messages by late 1901, and later won the Nobel prize for physics in 1909. Radio works in a very complicated way, but hereÕs a more simple explanation than youÕll get from most books: Electromagnetic waves of different wavelengths are produced by the transmitter, and modulations within each wavelength are adjusted to carry ÒencodedÓ information. The receiver, tuned to read the frequency the transmitter is sending on, then takes the encoded information (carried within the wave modulations), and translates it back into the sensory input originally transmitted. Many of the men who pioneered radio had designs for it. Marconi saw it as the best communication system and envisioned instant world-wide communication through the air. David Sarnoff ( later the head of RCA and NBC) had a vision of Òa radio receiver in every homeÓ in 1916, although the real potential of radio wasnÕt realized until after World War I.