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- History of Broadcasting: Radio, 1880-1919
- Electric Signal Transmissions
- conduction
- sending through a medium
- e.g., wires, metal, salt water, earth, telegraph
- induction
- current appearing next to another current
- e.g. interference
- radiation
- generation of electromagnetic waves
- light, heat, electricity
- e.g., using “ether" as a medium, radio!
- Waveform
- oscillation
- wavelength
- cycles
- frequency
- cycles per second
- Hertz (Hz)
- amplitude
- height of a wave
- e.g., watts or Bels
- Metric Prefixes
- 1015: peta
- 1012: tera
- 109: giga
- 106: mega
- 103: kilo
- 102: hecta
- 101: deca
- 10^–1: deci
- 10^–2: centi
- 10^–3: milli
- 10^–6: micro
- 10^–9: nano
- 10^–12: pico
- 10^–15: femto
- Measurements
- MHz: mega Hertz
- millimeter waves
- Electromagnetic Waves
- electromagnetism
- natural occurring
- discovered in 1820s
- James C. Maxwell
- Scottish physicist
- invisible electronic impulses similar to visible light
- published a paper, 1873
- explaining 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
- sending code through the “ether”
- wireless replacement for wired electromagnetic telegraph
- Guglielmo Marconi
- read Hertz’s paper, 1894
- built an elevated radio transmitter, 1895
- transmitted over two-mile distance
- patented wireless telegraph, 1896
- went to England
- British naval and commercial ships
- formed Wireless Telegraph and Signal Company, 1897
- commercial application for radio
- ship-to-shore communication
- Marconi Wireless
- British Marconi, 1900
- American Marconi subsidiary, 1902
- wireless transmission across English Channel (1899)
- wireless transmission across Atlantic Ocean (1901)
- Wireless Telephony
- carry voice instead of code
- defective for point-to-point
- effective for broadcasting
- 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 across New York, 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
- 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
- Two-Tier Radio Stations
- Class A Stations
- 360-meter band
- amateurs
- small businesses
- Class B Stations
- 400-meter band
- 500–1000 watts
- all live: no phonographic recordings
- "Bertha Brainard Broadcasting Broadway,” mentioned in Hilmes, beginning in 1922
- Early Radio Stations
- Westinghouse
- Frank Conrad
- KDKA Pittsburgh, 1920
- WJZ Newark, New Jersey, 1921
- RCA took over WJZ and WJY, 1923
- A&T opened WEAF, New York
- General Electric opened WGY, Schenectady, 1922
- 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
This outline is based on material from Michele Hilmes, Only Connect: A Cultural History of Broadcasting in the United States. 4th ed. Boston: Cengage, 2014; and Christopher H. Sterling and John M. Kittross, Stay Tuned: A History of American Broadcasting, 3rd ed. Mahwah, NJ: Lawrence Erlbaun Associates, 2002.