History Of Radio.

When asked, in 1938, to explain radio, Albert Einstein said: “You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles.
Do you understand this? Radio operates exactly the same way: you send signals here – they receive them there. The only difference is that there is no cat.”

Old Zenith radio receiver

 

It all started with the discovery of “radio waves,” or electromagnetic waves, that have the capacity to transmit music, speech, pictures, and other data invisibly through the air. It was during the 1860s that the existence of radio waves was predicted by the Scottish physicist James Clerk Maxwell, and only a bit later projected as rapid variations of electric current into space by the German physicist Heinrich Rudolph Hertz. Fascinated by Hertz’s earlier discovery, the Italian Guglielmo Marconi realized that they could be used for sending and receiving messages.

Guglielmo Marconi, the father of the radio.

The wireless telegraph arrived with the first radio signals sent in Italy in 1895. Patented the following year, Marconi’s first radio transmissions were coded signals that were transmitted less than 2 km distance.
Turned down by the Italian government for funding but convinced of the huge potential that this invention held, Marconi moved to England, patented the radio and experimented further. By the end of the 19^th century, Marconi’s telegraph was sending transatlantic messages in Morse code, quickly becoming a commercial success and the dominant means of wireless marine communication.

The radio in its early days.

 Although credited as the father and inventor of the radio, Marconi was not the first one who set foot into the unknown territory of wireless telegraphy. History says that the inventor Nikola Tesla demonstrated the first wireless radio in 1893 in Missouri and got the patent for his theoretical radio model in 1900; he is, therefore, often controversially acknowledged as the inventor of the radio even though he did not build the working radio.

A Deutsche Post stamp from 1995 to mark the 100th anniversary of the invention of the radio.

 In 1909, when Marconi shared the Nobel Prize in physics, the arctic explorer Robert E. Peary radio-telegraphed that he had found the Pole. The importance of wireless telegraphy became even more apparent during the First World War: the military used it almost exclusively, thus making it an invaluable communication tool.
The first time a voice, instead of the usual dots and dashes, came through wireless operators was on Christmas Eve in 1906, announcing the era of wireless telephony. The radio as we know it today came only in 1921. Marconi introduced the short wave transmission the following year.

A vintage radio shop.

In the years following the war, amateur radio operators in the United States and Europe started using the technology for long-distance telephone calls. The first broadcasting stations surfaced, playing music or reading newspapers.

The first radio advertisement was heard in 1923. Very soon, radio broadcasters usurped the newspapers, becoming the leading source of information for the public.The historic broadcast of the Pittsburgh-based station KDKA in 1920 marked the beginning of both radio broadcasting and the radio craze, making radios a product of the mass market. The demand for radio receivers was constantly increasing and by 1930, this must-have household fixture entertained 60% of all American families.

Radio-listening was a favorite pastime even during the Great Depression.

 Crystal radios were among the first radio models to be used and manufactured. Until the vacuum tube radios replaced them in the 1930s, crystal radios were the most widely used radio receivers because they did not require batteries or electric power but rather ran on radio waves. As such, they were ideal for use on farms, which were not electrified until the 1930s.

A US farmer listening to a crystal radio around 1922

Early radios, including the crystal ones, needed antennas to operate well. Striving to improve the radio altogether rather than the crystal model only, one inventive young man named Edwin Armstrong made the first radio using the vacuum tube. Emitting clearer sounds over great distances, the vacuum tube radios entered the market in 1924.

By 1925, over 6 million radio sets were purchased in the United States. More than 600 radio stations offered diversified programming, including popular and classical music, sporting events, fictional stories, newscasts, weather reports and political commentary. Edwin Armstrong invented frequency-modulated or the FM radio in 1933. The invention of the transistor in 1947 allowed radios to become small and portable, furthering the mass consumption of radio receivers in general. In 1954, Sony, a small Japanese company at the time, introduced the transistor radio.

A 1955 AM-only Toshiba vacuum tube radio model.

 The outbreak of the Second World War underlined once again the crucial role that radio had in relaying war news to the public and its function as the primary source of information. The boom in FM stations that America saw in the years during and following the war continued, and by 1960, nearly 750 FM stations provided entertainment to the masses, slowly overtaking the original AM stations. AM radios remained popular throughout the 1970s thanks to the already introduced concept of the car stereo. However, the early 1980s gave way to new forms of music and FM became an inseparable part of the new generation’s identity.

The AM radio stations survived the 1970s thanks to the old automobiles with car stereo systems.

 As controversial as any other discovery that changed the world in unprecedented ways, the radio would have been impossible without the crucial findings in electricity by many popular scientists who were working in the dark, and the efforts made by even more enthusiasts whose names will remain unknown forever. An integral part of everyday life, radio technology paved the way for today’s television broadcasters, satellite radio, Internet radio stations, wireless connectivity, mobile phones… and it is still moving forward.

Vintage-looking radio equipment.

Digital terrestrial radio, radio advertising and growing podcast audiences already indicate the future of this low-cost, flexible and far-from-dying medium. Over 33,000 radio stations and over 2 billion radio sets in use worldwide prove that the radio star is shining as brightly as it did over a century ago when it changed the world for the first time.

June 17, 2017 by Petra Bjelica

original source : http://www.wallswithstories.com/uncategorized/timber-framing-a-rediscovered-technique-for-building-a-home.html