History of Radio History of Mass Communication

Important Inventions  Electric dot and

dash telegraph  Telephone  Wireless telegraph  Radio telephone  Radio for mass use

 1844

 1876  1896  1906  Early 1920s

Morse Code Samuel Morse. 1844  Constructed a telegraph machine and

devised a code for each letter by using long and short pulses of electricity.

 He was able to attach a pencil to the piece of metal that his electromagnet attached so as to leave a record of the transmission on a moving strip of paper.

Morse Code Samuel Morse. 1844  Obtained grant from US Government  Strung copper wire on poles between

Baltimore, Maryland & Washington over 40 miles

 From Baltimore in 1844 he sent the message “what Hath God wrought?”

Samuel Morse

Telegraph Office of London Post Office

Transmitter/Receiver Heinrich Hertz. 1887  German Scientist constructed a simple

transmitter and receiver for radio waves

Wireless Telegraph Gugliemo Marconi. 1895  Synthesized Heinrich Hertz’s discoveries of

electromagnetic waves that travelled instantaneously without wires and the concept of transmitting messages encoded in dots and dashes via the electric telegraph

 American Marconi Company in 1899

Radiotelephone Reginald Fessenden. 1906  Christmas eve 1906, radio operators along

the Atlantic sea heard a voice reading from a Bible & record & violin playing

 Previously only heard dots and dashes

Radiotelephone Reginald Fessenden. 1906

Audion Lee De Forest. 1906   Audion: 3 element vaccuum tube whaich

made more sophisticated circuits and application to amplify signals

  Permitted the development of small receivers   Radio transmitters and receivers about the

size of a bread box played important roles in WW1

  By 1918, pilots could transmit and receive from an airline to the ground

Mass Radio  Maritime, Commercial and Government

Use to Mass Medium   Small enough for home use   Affordable   Regularly scheduled programs   Clear reception   Means of paying for broadcast

David Sarnoff

 Proposed to American Marconi Company to broadcast music, sports scores, lectures, weather reports, concerts

 Manager, Radio Corporation of America in 1919

Radio Programming

 Dr. Frank Comrad was developing transmitting systems for Westinghouse Corporation.

 He needed to test the equipment after hours, so he built a transmitter over his garage at home.

 Broadcast 2 evenings a week. People sent him postcards and called requesting Victrola records

First Commercial Radio Station KDKA, 1920  Broadcast of the Harding Cox presidential

election  A running account of the returns was

phoned in from a newspaper office and read over the air. In between announcements and Banjo music was palyed

Staff of KDKA

Radio Act 1912  Original bill initiated during investigations

re. sinking Titanic  US Federal law that mandated that all

radio stations in the US be licensed by the federal government

 Seagoing vessels continuously monitor distress frequencies

 Did not prescribe frequencies

Radio Act 1927  Government to regulate airwaves in the

interest of the people  Established the Federal Radio Commission  Broadcasting only on assigned

frequencies, specified power levels and scheduled times

 Replaced by Federal Communications Act of 1934

Mass Use  By 1922 half million sets were in use  By 1925 escalated to five million sets  By the end of the decade, 14 million radio

receivers were in American homes

Frequency Modulation Edwin Armstrong. 1933   Developed and patented a new radio signal   It was static free   Carried higher and lower audio frequencies

than amplified modulation (AM)   Ideal carrier for music   Court battle with RCA re. using the system for

TV broadcast   Committed suicide before the settlement

Discussion  Radio in the Great Depression. 1930s  Radio in WW ll. 1939 to 1945