History of the Radio

Now a day, radio is one of the most important Medias in our lives. It is an audio media that provides information to the listener from all around the world, without having to meet. It lets people communicate through a long distance, and gives them information about what is happening in this world. The nice advantage about the radio is that you are capable of doing whatever you want while you listen to it, without staying still and staring at it to focus on what is happening.

The history of radio started with a scientist called Heinrich Hertz, who caused spark to leap across a gap, and from that he detected radio waves in the year 1887. By the year 1893 he built an oscillator and a resonator.

By the year 1984 the scientists Oliver Lodge, Alexander Popov and Edward Brauley, filled a glass tube with metal filing that joint a coherer cohered under electromagnetic waves, and when they tapped the tube, filling collapsed and broke the circuit, that’s when they built a coherer that detects radio waves.
In 1940 Radio programming

On December 1894 in Italy, Gugielmo Marconi invented the spark transmitter, then in February 1896 he took his “black box” to Britain, despite it was broken he filed for the British patent. By 1897 Marconi formed his first wireless telegraph and formed a signal company, and in December 1898 he formed the world’s first radio factory.

Marconi’s company “The American Marconi co.” was formed in 1899, he controlled patents, and his company also sold spark transmitters to the U.S Navy for point-to-point transmissions.

In the year 1905, the Canadian Reginald Fessenden invented a continuous wave voice transmitter, he used a high frequency alternator that was developed by Charles Steinmetz, and in 1906 on Christmas Eve he made a voice broadcast over North Atlantic. In 1910, Fessenden sold to the westing house the patent for heterodyne receiver that used the joint operation of two AC currents for a third frequency.

In 1906 the inventor Lee de Forest patented his audion tube, in 1903 he visited Fressenden’s lab and stole a design for a “Spade detector”, and promoted the idea of multi-point broadcasting and sold patents to AT&T.

In 1903, Harold D. Arnold at AT&T developed the amplifying vacuum tube, that made the first coast-to-coast telephony, and in 1915 he made the first translated radio transmission.

In 1913 Edwin Armstrong patented the regenerative circuit that caused stronger oscillation in the tube that generated radio waves. In 1914 he made long-distance voice transmissions, and during the World War I he developed superhetrodyne circuit that combined high and low frequency waves, he sold patents to RCA in 1920, and in 1933he discovered FM transmission which was rejected by Sarnoff at RCA who was trying to develop television.

In 1915 De Forest sued Armstrong over the basic regenerative patent but lost the case in 1921, but in 1923 when it was demonstrated in court De Forest won the final battle, and was awarded the basic radio patent, which caused him to be known as the
“Father of radio.”

Charles Herrold began regular broadcasting in San Jose in 1912, and Fred Christian was broadcasting in Hollywood in his bedroom, William Scripps in Detroit broadcast music from office of his newspaper, the Detroit News, on station 8MK that became WWJ. Hiram Maxim of American Radio Relay League testified at congressional hearings in 1918. Then later on many had returned from world war I with experience using signal corps SCR-70 vacuum- tuber-radios- most popular were simple inexpensive crystal radio receivers rather than tube sets. Frank Cornad was engineer for Westinghouse, built SCR-70 receivers during war for signal corps and began broadcasting music from his garage in Pittsburgh- 8XK. In 1921 RadioShack Corporation was formed to sell equipment to “ham” operators, taking its name from the small wooden building for radio equipment on ships.

In 1912, due to the titanic disaster in April 14, all ships were forced to have radios with 2 operators and back up power and all transmitters had to be licensed.