The Invention of Radio

Invention of Radio

Radio was initially imaged as a wireless telegraph; the idea of broadcasting was a separate invention

The Wireless Telegraph:

based on the work of physicists such as Faraday going back to the late 1820s--some people had seen the possibility of wireless telegraphy, but had not been able to transmit (via induction) for more than a mile or two. James Clerk Maxwell and Heinrich Hertz developed the theory of electromagnetic waves. Hertz even detected them with a spark, but it took Lodge's coherer (iron filings that organized themselves to conduct electricity when hit by electromagnetic waves) before this was something usable.
Guglielmo Marconi used sparks to create radio waves. He grew up in Italy the son of an Italian father and a Scotch-Irish mother, got a mostly informal education (he got permission to sit in on university classes and work in a laboratory but did not actually enroll as a student), and decided to devote himself to make wireless telephony practical. This took a lot of trial and error, but by 1895 he had a system that would transmit many miles. His mother was convinced of the potential and took her son to England, where she thought the market would be better. The family decided to form their own company, which set out to get patents all over the world, and to publicize the new invention by publicity stunts. In 1899 Marconi sucessfully linked England and France across the English channel (where there was already a cable)--more significant was transmission from ships.
there was a great deal of journalistic enthusiasm for the idea of a wireless telephone--both providing communication where there were no lines and breaking the monopoly of the telephone and telegraph companies. Marconi transmitted signals across the Atlantic in 1901. He then set out to build and protect a business, for example insisting that his stations not communicate with ships using rival apparatus--much to the displeasure of the newspapers who were customers.

Marconi (left) at time of first successful transatlantic test

The PR was good but the market was limited, except for shipping and the military potential (and interference limited the number of signals that could be carried--you quickly got crowding between military, amateurs, and wireless telegraphy companies). Newspapers picking up military broadcasts and amateurs making up disasters for fun raised the need for regulation.
Lee de Forest , trained at the scientific school at Yale and determined to be an inventor, set out to compete with Marconi in building a wireless system. He was good at publicity but the business claimed more than it could deliver. De Forest was successful sued for stealing a key idea from Reginald A. Fessenden . De Forest lost this company , but kept rights to an invention called the audion, the first vacuum tube amplifier. This made it practical to transmit the human voice instead of Morse Code. In 1907 he successfully transmitted the human voice. He did some experiments with broadcasting, but his company collapsed and he was accused of stock fraud.
Edwin Howard Armstrong started as a teenager as a radio amateur, was a star student in electrical engineering at Columbia. In 1912 he figured out how to improve the audion dramatically (he understood it, which deForest never had). In 1914 Armstrong demonstrated his idea to the Marconi Company, where David Sarnoff realized its importance.

artist's rendition of the sinking of the Titanic Towards a larger market:

When the Titanic his an iceberg on April 15, 1912, one of the ship's wireless operators immediately began sending distress signals .

These were picked up in New York and by two other ocean liners about 12 hours away, but nearby ships did not get the message because their wireless operators were asleep, and it took the Titanic less than 3 hours to sink.
The California was less than 20 miles away, but the wireless operator was asleep and the wireless wasn't operational anyway because the captain had shut down the engines for the night rather than try to move in an icefield in the dark. If the California had heard the distress signal almost all the passengers could have been saved.
Another ship, a freighter, was within 30 miles, but did not have a wireless at all.
Only one nearby ship--the Carpathia, 58 miles away--got the message, only because its operator went back to the wireless room to check a time signal after he had finished his work for the evening.
Once the tragedy was know, amateurs filled the airwaves with inquiries and cruel rumors (possibly because they had lumped together the message that the Titanic had hit an iceberg and another message about a different ship being towed to shore). One of the results of the disaster was radio regulation, licensing amatuers and limiting them to wavelengths of 200 meters or less.

lifting of patent restrictions in WWI led to an explosion of innovation of devices using vacuum tubes
GE had bought Marconi, Westinghouse had key circuit patents--you needed cross-licensing in order to make anything
In 1911 AT&T turned their laboratory into an Industrial Research Laboratory

bought Lee de Forest's patent on the audion and used it for amplification of telephone lines, but also thought they might get into what they called wireless telephony as a feeder for the telephone system
AT&T finally got out of the radio business by trading for new patents they needed to keep their monopoly on the telephone.

the Navy was frustrated with dealing with British Marconi patents, which meant cooperating with the British government more than they wanted. So they encouraged GE, AT&T and Westinghouse to form the Radio Corporation of America in 1919. The goal was to compete with foreign domination of international transmission.
RCA inherited from the Navy and the Marconi company a focus on the model of point to point communication.
but David Sarnoff , who even before the war had been made head of advanced technology at Marconi, already believed in the potential of broadcasting. Sarnoff was the businessman who made radio commercially feasible, a poor immigrant who became president of RCA.

The invention of broadcasting:

Westinghouse had another idea, started commerical radio broadcasts in 1920--a real leap of imagination
Some amateurs had already started broadcasting between 1913 and 1915--it was like having you own web page, and also a good activity for high school and college radio clubs. When de Forest sold his patent rights to AT&T he kept the rights to broadcast news and music, something that AT&T thought was a frivolous activity for amatuers. But deForest dreamed of bringing concert performances (and particularly opera) to the homes of people who couldn't attend. In Oct 1916 he broadcast the Yale-Harvard football game and the presidential election.
When the U.S. declared war on Germany the government tried to close down all amateur radio stations (and get the operators into the military, which was very short on operators). When the war eneded the operators wanted to get back to their hobby, and were unhappy about the ban on transmitting that remained in effect for almost a year after the war.
Once the ban was lifted amateurs like Frank Conrad in Pittsburgh began to move towards a commercial station--broadcasting music on a regular schedule and then getting records for free from a local merchant in return for mentioning the store's name on the air. A local department store began advertising and selling simple receivers to listen to Conrad's broadcasts. And it happened that Conrad's day job was working for Westinghouse.
Westinghouse was making money selling to the amateur market, and began to realize that this was not just a few technology enthusiasts. The vice president of the company saw a newspaper story about Conrad's broadcasts, and the company decided they might sell more radio sets if they broadcast on a regular basis--Nov. 2, 1920 they broadcast election results. This got popular enthusiasm, and by 1922 a large number of stations were set up by amateurs and by department stores, newspapers, and the companies that made radios. A radio boom started getting attention from the press in 1922.

KDKA station, Pittsburgh

But how do you get people to pay? First companies started sponsoring entertainment--the Ivory Soap singers--and that eventually evolved into advertising.
There was talk of government patronage or a licensing fee to fund broadcasting, but that sounded too socialistic. In 1922 an AT&T run station in New York ran a 10 minutes advertisement for a Long Island real estate developer. As stations found ways of financing themselves the boom spread--at one point in the 1920s 1/3 of the sales of furniture was actually radios. ( women in radio )
1926 Sarnoff helped created the first broadcasting network, NBC.
for more information A timeline of radio or radio history links

1926 Silvertone Receiver