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- Media Technologies: Television
- Television is Old
- Mechanical Television
- mechanical scanning
- spinning disks
- Nipkow Disk
- Baird Television
- Nipkow Disk
- Paul Gottlieb Nipkow, 1885
- spinning disk
- selenium cell
- light projects image
- low-resolution
- 30–100 holes
- 10–18–inch image
- Bard Transmitter
- John Logie Baird, 1926
- live moving images, 1926
- 12.5 pictures per second
- 30-lines of resolution
- Baird is considered one of the inventors of electronic television
- Electronic Television
- image on an electron plate (11,22)
- electronic scanning (19)
- line-by-line (16)
- signal carried over wire (23)
- projected on a remote screen (30) over wire or radio.
- Image Dissector
- electronic video camera tube
- replaced disks with cesium
- Philo T. Farnsworth, 1921
- Idaho amateur inventor
- won a patent suit vs. RCA, 1935
- basis for all TV tubes until late 20th century
- Vladimir Zworkin
- electronic television at Westinghouse, beginning 1923
- recruited by RCA, 1930
- visited Farnsworth
- saw demonstration of image dissector
- Iconoscope
- electronic video camera tube
- used cesium and silver
- detect light
- create electronic charge
- pixels into mosaic
- more sensitive to light than image dissector
- Kinescope
- electronic video projecting tube
- electronic signal
- electron gun
- illuminates phosphorescent screen
- World of Tomorrow
- New York
- RCA Pavilion
- David Sarnoff
- television
- introduced electronic television
- transmitted by radio
- 1939 World’s Fair
- Futurama
- Suburbanization
- post-World War II
- flight from urban housing
- mass-produced housing
- Interstate highways
- Television at Home
- initially they listened to radio
- away from downtown theaters
- families became more selective about entertainment
- television became domestic “window on the world”
- National Television Systems Committee
- NTSC, group of electronics firms, including RCA
- analog standard TV for US, 1941–2009
- 525-lines
- 60 Hz (fields per second)
- interlaced: odd and even fields
- 30 frames per second
- FCC Freeze
- instituted September 30, 1948
- “freeze” on new licenses
- standard for color television
- additional spectrum space
- educational TV channels
- reduction of radio interference
- lifted April 14, 1952
- Color Format War
- CBS Color
- four-color system
- introduced 1951
- not compatible with older B&W TV receivers
- RCA Color
- three-color system
- introduced 1953
- backward compatible with B&W receivers
- image would be in B&W
- FCC selected RCA Color for NTSC Color, 1954
- Electromagnetic Frequencies
- cycle per second = 1 Hz
- 1 kilohertz (kHz) = 103 Hz
- 1 megahertz (MHz) = 106 Hz
- 1 gigahertz (GHz) = 109 Hz
- 1 terahertz (THz) = 1012 Hz
- 1 petahertz (PHz) = 1015 Hz
- 1 exahertz (EHz) = 1018 Hz
- Television Spectrum
- Channels
- Very High Frequency
- Ultra High Frequency
- Very High Frequency
- VHF low-band
- VHF high-band
- requires channel separation between adjacent channels
- Ultra High Frequency
- UHF
- channels 14–69
- required less channel separation
- expanded available channels
- UHF vs. VHF
- FCC decided intermixture of VHF and UHF frequencies
- FCC did not require TV sets to receive UHF stations until 1960
- Result:
- VHF stations proliferated
- UHF stations languished
- Sales of TV Sets in United States
- Rapid Adoption
- Effect of Freeze
- TV networks from radio
- pre-Freeze stations
- owned-and-operated
- network affiliates
- UHF stations did not proliferate
- Network Oliopoly
- Community Antenna TV
- Community Antenna Television, 1948
- rural Pennsylvania, rural Oregon, and Manhattan
- terrain blocked TV reception
- distant signal importation
- considered piracy by broadcasters, until 1960s
- Satellite Cable
- Satcom I, 1975
- geostationary satellite
- continental footprint
- launched cable networks
- HBO and WTBS
- Showtime, ESPN, Nickelodeon, Weather Channel
- Multichannel Universe
- specialty channels
- shopping channels
- 24-hour news channels
- pay-per-view
- timeshifting: VCR and PVR
- video-on-demand
- subscription streaming services
- Superstation
- Ted Turner, WTBS
- UHF TV station, Atlanta
- expanded reach via satellite
- programming was like broadcast network
- off-network reruns
- syndicated program
- no local programming