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Radio is the technology of communicating using radio waves. [1] [2] [3] Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves.
- Overview
- Radio’s early years
Radio is sound communication by radio waves, usually through the transmission of music, news, and other types of programs from single broadcast stations to multitudes of individual listeners equipped with radio receivers.
Was radio used in World War I?
Efforts were made to use radio in World War I, but the technology proved unreliable. Wireless sets were available in battlefield trenches, where they were reserved for emergency communication in the event of cut telephone and telegraph wires.
Where are radio waves located on the electromagnetic spectrum?
Radio waves are located at the low-frequency end of the electromagnetic spectrum, beneath gamma rays, X-rays, ultraviolet light, visible light, infrared radiation, radar waves, microwaves, and television waves.
Where was radio invented?
The first voice and music signals heard over radio waves were transmitted in December 1906 from Brant Rock, Massachusetts (just south of Boston), when Canadian experimenter Reginald Fessenden produced about an hour of talk and music for technical observers and any radio amateurs who might be listening. Many other one-off experiments took place in the next few years, but none led to continuing scheduled services. On the West Coast of the United States, for example, Charles (“Doc”) Herrold began operating a wireless transmitter in conjunction with his radio school in San Jose, California, about 1908. Herrold was soon providing regularly scheduled voice and music programs to a small local audience of amateur radio operators in what may have been the first such continuing service in the world.
The radio hobby grew during the decade before World War I, and the ability to “listen in” with earphones (as there were no loudspeakers) and occasionally hear voices and music seemed almost magical. Nevertheless, very few people heard these early broadcasts—most people merely heard about them—in part because the only available receivers were those handmade by radio enthusiasts, the majority of them men and boys. Among these early receivers were crystal sets, which used a tiny piece of galena (lead sulfide) called a “cat’s whisker” to detect radio signals. Although popular, inexpensive, and easy to make, crystal sets were a challenge to tune in to a station. Such experiments were scattered, and so there was little demand for manufactured receivers. (Plug-in radio receivers, which, through the use of loudspeakers, allowed for radio to become a “communal experience,” would not become widespread until after 1927.) Early broadcasters in the United States, such as Herrold, would continue until early 1917, when federal government restrictions forced most radio transmitters off the air for the rest of World War I, stalling the growth of the medium.
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After the war, renewed interest in radio broadcasts grew out of experimenters’ efforts, though such broadcasts were neither officially authorized nor licensed by government agencies, as would become the practice in most countries by the late 1920s. Early unauthorized broadcasts sometimes angered government officials, as in England, where concern was raised over interference with official government and military signals. Amateurs developed the means and simply began to broadcast, sometimes preannounced but often not. As they became more proficient, they would announce schedules—typically an hour or so for one or two evenings per week.
One of the world’s first scheduled radio broadcast services (known as PCGG) began in Rotterdam, Netherlands, on November 6, 1919. Other early Dutch stations were operated by the Amsterdam Stock Exchange (to send information to new members) and by a news agency that was seeking a new way to serve newspaper subscribers. Another early station appeared in Canada when station XWA (now CFCF) in Montreal began transmitting experimentally in September 1919 and on a regular schedule the next year. (The first commercially sponsored stations in Canada appeared in 1922.) The first British station offered two daily half-hour programs of talk and music from Chelmsford (near London) in 1919–20. Concerns about interference with military wireless transmissions, however, led to a shutdown until 1922, when government-authorized stations appeared, including the first London-based outlet. The first Mexican radio station aired in the capital city in 1921, though many in the country had first heard broadcasts from Cuba or Puerto Rico. By that point, stations had also appeared in Australia (Melbourne, in 1921), New Zealand (from Otago University in Dunedin, also in 1921), and Denmark (from Copenhagen, 1923).
May 20, 2022 · A radio is a box filled with electronic components that catches radio waves sailing through the air, a bit like a baseball catcher's mitt, and converts them back into sounds your ears can hear. Radio was first developed in the late-19th century and reached the height of its popularity several decades later.
May 30, 2023 · The tuner causes the radio to receive just one sine wave frequency (in this case, 680,000 hertz). Now the radio has to extract the DJ's voice out of that sine wave. This is done with a part of the radio called a detector or demodulator. In the case of an AM radio, the detector is made with an electronic component called a diode.
- You can listen to radio on your computer, though it is streamed digitally via your internet connection. Search online for your favorite station to...
- Some radio stations have their own apps for listening via smartphone. The TuneIn app is a great way to browse and listen to popular radio stations....
- There's quite a bit of debate about whether radio is on it's way out or not. Streaming music has provided some steep competition to traditional rad...
Radio technology, transmission and detection of communication signals consisting of electromagnetic waves that travel through the air in a straight line or by reflection from the ionosphere or from a communications satellite. Learn more about the history, development, and principles of radio technology in this article.
The radio is a device that has revolutionised the way we communicate. It got invented by Italian physicist and engineer Guglielmo Marconi in the late 19th century. Marconi’s innovative ideas and determination led him to do this. He experiments with wireless telegraphy and sends signals over long distances.
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What does radio mean?
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What is radio technology?
History of radio. The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy".
