mechanical tv vs electronic tv. mechanical tv 1884 paul nipkow –invented nipkow disk spinning disk...
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Mechanical TV vs Electronic TV
Mechanical TV
• 1884 Paul Nipkow –Invented Nipkow disk
Spinning disk & photoelectronic tubes
improved by Jenkins and Baird in Englandhttp://www.youtube.com/watch?v=92dN2G5-D4c
BellBell LabsLabs
http://www.earlytelevision.org/ge_mechanical.htlhttp://www.earlytelevision.org/ge_mechanical.htl
General Electric
http://www.earlytelevision.org/homemade.html
Mechanical TV had poor picture quality and mechanical parts that
could break or wear out.• Paramount Astoria girls, 21st April 1933
http://www.tvdawn.com/recordng.htmhttp://www.tvdawn.com/recordng.htm
Electronic TV
• Zworykin RCA scientist- iconoscope tube
• Cathode Ray Tube
Philo Farnsworth
• demonstrated the first all-electronic television (1927) basis of
current electronic televisions
• No mechanical parts all electronic
• lost later patent battles to RCA.
Electron Gun
• Scans image
line by line and transmits
convert light into electric signal and sending over by radio waves to a receiver.
Illusion of Motion
• 1877 Edward Muybridge To settle a bet
• Still pictures projected fast seem to move
• Film - 24 frames per second• Television -30 frames per
second
Television and the Depression
1930’s Golden Age of RadioPopular and Profitable
Television technology ready to be introduced but still experimental and expensive.
RCA stalling Farnsworth in court
http://xroads.virginia.edu/~1930s/DISPLAY/39wf/front.htm
1939 Television Introduced 1939 Television Introduced
To prove to To prove to skeptical New skeptical New York World's Fair York World's Fair visitors that no visitors that no trickery was trickery was involved in involved in creating television creating television images, a special images, a special order was made to order was made to RCA's engineering RCA's engineering wing to build a wing to build a transparent transparent version of Vassos' version of Vassos' TRK-12 cabinetTRK-12 cabinet.
www.mztv.com/worldhome.html
RCA Pavilion 1939 World’s FairRCA Pavilion 1939 World’s Fair
Very popular exhibit but few TV’s soldVery popular exhibit but few TV’s sold - few programs on air- few programs on air-cost of a TV is the same as a car-cost of a TV is the same as a car
20 April 1939, RCA chairman David Sarnoff20 April 1939, RCA chairman David Sarnoff
http://www.terramedia.co.uk/Chronomedia/picture_pages/1939_worlds_fair.htm
President Franklin Roosevelt, as he appeared on TV screens at the opening of the Fair. It was the first of only two live appearances he made on TV during
his 12 years as President.
http://web.cnjnet.com/~mweinber/nyfair.htmlhttp://web.cnjnet.com/~mweinber/nyfair.html
World War II• 1941 Government stops broadcasts and manufacturing of setsCathode Ray Tubes used for Radar
War improves technologytrains people and brings down price1946 Manufacturing allowed
V.H.F. or U.H.F.
• V.H.F. very high frequency –limited channels with a strong signal
• U.H.F. ultra high frequency – many channels with a weak signal.
• First stations V.H.F. very few stations in a market. Follows the corporate pattern of Radio.
1949 Everything is in place
Signal is standardized Black & WhiteAffordable TV sets ($200-$500)
(Ford car: $1339-$2262)
Locally available
Regular Popular Programming
(Programs sell sets)