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- Week 11, Radio
- Electromagnetic Waves
- invisible electronic impulses similar to visible light
- discovered by James Maxwell in the 1850–60s
- radio waves could be harnessed
- transmission (Tx)
- reception (Rx)
- Heinrich Hertz: first documented Tx & Rx of radio wave, 1880s
- Wireless Telegraphy
- Guglielmo Marconi
- ship-to-shore communication
- patented wireless telegraphy (1896)
- Marconi Wireless Telegraphy Company (1897)
- British naval and commercial ships
- American Marconi (1899)
- wireless transmission across English Channel (1899)
- wireless transmission across Atlantic Ocean (1901)
- Wireless Telephony
- 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
- Edward Alexanderson
- Reginald Fesseden
- first voice transmission on Christmas Eve 1906
- Edwin H. Armstrong
- regeneration
- amplification using deForest’s audion
- developed during World War I
- broadcasting
- transmission of radio waves to a broad public audience
- “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”
- Radio Corporation of America
- after World War I, debates to nationalize radio
- 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
- Early Radio Stations
- Westinghouse
- Frank Conrad
- KDKA Pittsburgh, 1920
- WJZ Newark, New Jersey, 1921
- RCA
- took over WJZ and WJY, 1923
- A&T
- General Electric