Juan Monroy — Media Technologies: Class 11, Magic of Radio

1 Electromagnetic Waves
- 1.1 invisible electronic impulses similar to visible light
- 1.2 discovered by James Maxwell in the 1850–60s
- 1.3 radio waves could be harnessed
  - transmission (Tx)
  - reception (Rx)
- 1.4 Heinrich Hertz: first documented Tx & Rx of radio wave, 1880s
2 Wireless Telegraphy
- 2.1 Guglielmo Marconi
  - ship-to-shore communication
  - patented wireless telegraphy (1896)
- 2.2 Marconi Wireless Telegraphy Company (1897)
  - British naval and commercial ships
- 2.3 American Marconi (1899)
- 2.4 wireless transmission across English Channel (1899)
- 2.5 wireless transmission across Atlantic Ocean (1901)
3 Wireless Telephony
- 3.1 Lee deForest
  - Wireless Telephone Company (1902)
  - based on the Fleming Tube (based on the electric light bulb)
  - audion triode vacuum tube (1907)
  - detected and amplified radio signals
- 3.2 Edward Alexanderson
  - alternator
- 3.3 Reginald Fesseden
  - first voice transmission on Christmas Eve 1906
- 3.4 Edwin H. Armstrong
  - regeneration
  - amplification using deForest’s audion
  - developed during World War I
- 3.5 broadcasting
  - transmission of radio waves to a broad public audience
4 “Great Man” version of history
- 4.1 Empire of the Air
- 4.2 Characters
  - Guglielmo Marconi
  - Lee DeForest
  - David Sarnoff
  - Edwin Armstrong
- 4.3 Driven men
- 4.4 “One would succeed on his own terms”
5 Radio Corporation of America
- 5.1 after World War I, debates to nationalize radio
- 5.2 March 1919: General Electric bought Marconi’s American division
- 5.3 October 1919: General Electric formed RCA subdivision
- 5.4 patent pool
  - General Electric (founding member)
  - American Marconi (acquired 1919)
  - Westinghouse (joined 1920)
  - American Telephone and Telegraph (joined 1920)
  - United Fruit (minor partner 1921)
- 5.5 delegated business
  - AT&T: radio transmitters and radio telephony
  - GE & Westinghouse: radio receivers
6 Early Radio Stations
- 6.1 Westinghouse
  - Frank Conrad
  - KDKA Pittsburgh, 1920
  - WJZ Newark, New Jersey, 1921
- 6.2 RCA
  - took over WJZ and WJY, 1923
- 6.3 A&T
  - opened WEAF, New York
- 6.4 General Electric
  - WGY, Schenectady, 1922