Radio day

Silence all day, and in the meantime I want to congratulate all workers in the communications industry on their professional holiday, the day of the radio.

On May 7 (April 25, old style) of 1895, the Russian physicist Alexander Popov demonstrated a radio communication session. For the first time this date was solemnly celebrated in the USSR in 1925, and since 1945 the holiday is celebrated annually.
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History and invention of radio

The creator of the first successful system of information exchange using radio waves (radio telegraphy) is considered to be the Italian engineer Guglielmo Marconi (1895). However, the work of Marconi was met without enthusiasm.

In Russia, A. S. Popov is traditionally considered the inventor of radiotelegraphy, however, both of them are not quite right. Marconi, in fact, connected the transmitter of Heinrich Hertz and the receiver of A. S. Popov into one device. In the first experiments on radio communications, conducted in a physical office, and then in the garden of the Mine Officer Class, the receiver detected the emission of radio signals sent by the transmitter, at a distance of up to 60 m.

In commemoration of the 50th anniversary of the invention of the radio by the Russian scientist A. S. Popov, executed on May 7, 1945, the Council of People's Commissars of the USSR decided: taking into account the crucial role of radio in the cultural and political life of the population and for the defense of the country and technology in the field of radio and the promotion of radio amateur among the general population, to establish on May 7 the annual "Day of Radio".

In the United States, Nikola Tesla, who patented a radio transmitter in 1893, and a receiver in 1895, is considered the inventor of radio. The design of Tesla's devices made it possible to modulate the oscillator circuit of the transmitter with an acoustic signal, transmit the signal over a distance and receive it by the receiver, which converted the signal into an acoustic sound. All modern radio devices based on the oscillating circuit have the same design. While the design of Marconi and Popov were primitive and allowed only a signal function, including using Morse code.

In France, the inventor of coherer (the Branly tube) (1890) Edouard Branley was long considered the inventor of wireless telegraphy.

In India, Jagadish Chandra Bose demonstrates radio transmission in the millimeter range in November 1894.

In Great Britain, in 1894, the inventor of the coherer (Branly tube with a shaker) Oliver Joseph Lodge demonstrates radio transmission and radio reception for a distance of 40 meters. The first inventor of the methods of transmitting and receiving electromagnetic waves (which for a long time were called “Hertzian Waves Waves”) was their own discoverer, the German scientist Heinrich Hertz (1888).

The invention of radio communications gave rise to such sciences as radio astronomy, radiometrology, radio navigation, radio intelligence, radio resistance.

Read more on the wiki: http://ru.wikipedia.org/wiki/Day_radio