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Heinrich Rudolf Hertz was the first scientist who was able to transmit electromagnetic waves through the air. Also known as radio waves. He proved Maxwells electromagnetic theory
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Guglielmo Marconi was a young italian inventor. He started building a commercial wireless telegraphy system using Hertzian waves. He raised his antenna and made other changes and made the distance of the transmitter go farther.
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Reginald Fessenden used an Alexander alternator and rotary spark gap transmitter to make the first radio audio broadcast. Happened in Brant Rock, Massachusetts. He sent a broadcast of him playing the violin to ships.
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Charles David Herrold, an electronics instructor in San Jose, California constructed a broadcasting station. Used spark gap technology but modulated the carrier frequency with a human voice and later music. Later became was is known today as KCBS.
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Harold J. Power and his radio company broadcasts the first continual in the world from Tufts university. The broadcast laster 3 hours. Company later became first to broadcast on a daily schedule and to broadcast radio dance programs, university professor lectures, the weather, and bedtime stories.
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Most common type of receiver before vacuum tubes. Still pursued as a hobby to use these type of recievers. As the only energy available is by the antenna system, loudness is necessarily limited.
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It is to known as KDKA in Pittsburg, Pennsylvania. October 1920 got its license and went on the air as the first US licensed commercial broadcasting station and on November 2, 1920 with the presidential election results
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Edwin Armstrong an inventor started FM in 1933. The first experimental FM radio station wasn't until 1937 by W1XOJ. It was granted by a construction permit by the US Federal Communications Commission.
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Regency introduced this transistor in 1954. It was powered by a standard 22.5V Battery.
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In 1955, the newly formed Sony company introduced its first transistorized radio. It was small enough to fit in a vest pocket.
