History of Radio - Radio is a science of transmitting data...

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Radio is a science of transmitting data without wireless to a remote point where a receiver detects the signal. In common terms we think about radio in the context of FM or AM stations that broadcast a radio announcer speaking and playing music but in fact radio waves are also used for sending and receiving data such as satellite broadcasts, Bluetooth devices and Wi-Fi networks. The history of radio dates back to the mid-1800s with the theoretical discussions of electricity and magnetism being related to each other. The telegraph system was the first direct commercially practical technology to be developed from this discovery, although telegraph required fixed wire cables and could only be transmitted from point to point and it needed human operators to retransmit a signal over long distances. The first wireless experiments were not carried out until James Maxwell had developed his own theories and incorporated the experiments of Michael Faraday into the unified theory of electromagnetism in 1865. Over the next decade several amateurs and physicists like William Henry Ward, Mahlon Loomis and Thomas Edison patented methods of sending and receiving a wireless telegraph system but none of these people had ever demonstrated a working system. Things changed in 1884 when Temistocle Calzecchi-Onesti invented a device which was subsequently refined and then named a coherer by Edouard Branly in 1886. The coherer became the enabling technology that could receive early radio signals, it is a glass tube filled with metal filings and connected to an electrical current which produced an audible click in a sounder while the signal was being received. Heinrich Hertz had refined a system by 1887 that allowed him to experiment with sending wireless signals to a wireless receiver, he is credited with being the first person to intentionally transmit and also receive a wireless signal. Strangely Hertz had no interest in the technology and was simply experimenting with practical electromagnetic waves to advance his theories but his research paved the way for other and more commercially adjusted inventors. Hertz was honored in 1933 when the unit of measure of radio and electrical frequencies was
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History of Radio - Radio is a science of transmitting data...

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