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- Introduction to Electronic Media
- Class 3, Roots of Broadcastng
- Electromagnetic Waves
- electromagnetism
- natural occurring
- discovered in 1820s
- James C. Maxwell
- Scottish physicist
- invisible electronic impulses similar to visible light
- 1850s–1860s
- discovered radio waves
- Heinrich Hertz
- German physicist
- built on Maxwell’s theory of electromagnetism
- successfully harnessed radio waves
- 1880s
- dipole resonator
- transmission (Tx)
- reception (Rx)
- Wireless Telegraphy
- Guglielmo Marconi
- patented wireless telegraphy (1896)
- commercial application for radio
- ship-to-shore communication
- Marconi Wireless Telegraphy Company (1897)
- British naval and commercial ships
- American Marconi subsidiary (1899)
- wireless transmission across English Channel (1899)
- wireless transmission across Atlantic Ocean (1901)
- Wireless Telephony
- Reginald Fesseden
- high-speed alternator-transmitter
- continuous wave at high-frequency
- consistent frequency
- modulated amplitude
- first audible transmission
- Brant Rock, Massachusetts
- Christmas Eve 1906
- recorded music
- live violin performance
- holiday readings
- Lee DeForest
- audion tube 1906
- based on the John Ambrose Fleming Tube (based on the
electric light bulb)
- triode: three-electrodes
- detected and amplified radio signals
- used in radio oscillators and receivers
- ship-to-shore audio transmission 1907
- broadcast from Metropolitan Opera House 1910
- Ernst Alexanderson
- Alexanderson alternator
- long-distance radio transmitter
- long-waves
- Transatlantic radio transmission
- Edwin H. Armstrong
- regenerative circuit
- amplify signal
- loop/circuit
- developed during World War I
- heterodyne principle
- two frequencies
- make a new hybrid frequency
- superheterodyne
- high-volume
- high-frequency
- basis for all radio transmitters and receivers
- wireless telephony
- amateur radio operators
- crystal sets
- pre-World War I
- Hugo Gernsback, Radio League of America
- Hiram Percy Maxim American Radio Relay League (ARRL)
- pushed aside by corporate interests
- “Great Man” version of history
- Empire of the Air
- Characters
- Guglielmo Marconi
- Lee DeForest
- David Sarnoff
- Edwin Armstrong
- Driven men
- “One would succeed on his own terms”
- World War I
- US seizes radio stations
- US nationalizes radio
- radio was an important military communications technology
- Early Radio Stations
- amateurs
- small businesses
- Westinghouse
- Frank Conrad
- KDKA Pittsburgh, 1920
- WJZ Newark, New Jersey, 1921
- Class A Stations
- Class B Stations
- 400-meter band
- 500–1000 watts
- all live: no phonographic recordings
- “Bertha Brainard Broadcasting Broadway”, mentioned in Hilmes,
beginning in 1922
- RCA
- took over WJZ and WJY, 1923
- A&T
- General Electric
- Hilmes: “radio would ultimately be a commercial medium in private
hands” (49)
- Radio Corporation of America
- March 1919: General Electric bought Marconi’s American division
- October 1919: General Electric formed RCA subdivision
- patent pool
- General Electric (founding member)
- American Marconi (acquired 1919)
- Westinghouse (joined 1920)
- American Telephone and Telegraph (joined 1920)
- United Fruit (minor partner 1921)
- delegated business
- AT&T: radio transmitters and radio telephony
- GE & Westinghouse: radio receivers
- Toll Broadcasting
- AT&T, 1923
- allowed individuals and businesses to buy blocks of time
- similar to using a telephone booth
- first established at WEAF, New York
- Network Broadcasting
- economies of scale
- originate a program in New York
- distribute over AT&T telephone land lines across the country
- allowed AT&T to expand “toll broadcasting” to a national level
- The Eveready Hour
- sponsored by National Carbon Company
- promote Eveready batteries
- launched December 4, 1923
- stage variety program
- Emcee Graham MacNamee
- National Broadcasting Company
- AT&T sold its radio interests to RCA, July 1926
- RCA announced new “NBC” networks
- NBC Red
- former AT&T stations
- WEAF, flagship
- NBC Blue
- RCA stations
- WJZ, flagship
- RCA dominance
- radio transmission
- radio receivers
- radio programming