TELEVISION: HOW IT WORKS 1952 CORONET INSTRUCTIONAL FILM CATHODE RAY TUBE ORTHICON XD39134

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This black-and-white educational film from 1952, “Television: How it Works” was created with educational collaborator Marvin Camras and produced by John Smart. The film explains the science of TV signal transmission. Credits (0:18–0:29): “Educational Collaborator: Marvin Camras, Senior Physicist, Armor Research Foundation, Illinois Institute of Technology, Sound RCA System.” Fade up on skyscraper with TV tower viewed from street-level (0:29). Door labeled “control room – no admittance” (narrator: “inner sanctum of a television station”) (0:40). Two men at switchboard pressing buttons (hands) (0:40). Young man in button-down shirt switches on home TV set (0:55). Zoom: screen. Flipping through TV channels: view of harbor (“news”), man performing on stage (“entertainment”), two people conducting physics experiment using bell (“education”), man diving in front of audience (“sports”), woman displaying stove and oven (“advertising”). Now on set of same kitchen commercial (1:34)—we see woman acting in front of camera while technicians operate. Actor is handed prop (poster: “see it at your local dealer”). Camera manually zooms (to display poster). Narrator begins explaining electron beam and its role in transmission over footage of hand turning off TV receiver, leaving faint mark on screen (1:54). Blank receiver tube, then cartoon of same (2:07). Diagram: “cathode-ray tube,” including “cathode” / “electron gun” which shoots stream of electrons at tube’s face. “Fluorescent coating” glows when struck to produce images. A technician takes apart TV camera on set of kitchen commercial (2:49). Cameraman pulls out image orthicon tube from behind lens. Zoom: technician holding tube, then tube with label (“image orthicon”). Diagram overlays image to explain physics, including: “electron gun” firing electrons to “target,” which receives signal via “lens,” which receives signal via “sensitive plate” (therein varying magnitude of electron beam, which returns back to gun). Single white dot appears on screen, then black dot; they merge to form grey dot (3:49). Return to diagram of camera tube, showing how image of dot is captured via lens on plate, setting up charge on target (depending on brightness), ultimately changing electron beam returning from firing electron gun. Changed beam is amplified and sent out by tube (latter not pictured). Diagram of transmitter shown, with camera / cameraman at right. Signal (depicted by arrows) reaches amplifier, which combines signal with carrier wave generator for transmission off-screen (4:27). Moving line representing signal (i.e., image being transmitted) shown moving up antennae and then being radiated out in concentric waves (4:39). Receiver antennae on roof of house (4:47) receives signals from waves. Signal travels downward through lead-in wires inside. Same tube receiver diagram from before shows electron gun firing at screen, displaying image of dot (4:56). Words appear on screen detailing process in order with simple illustrations: “image of light,” “electricity,” “transmitter waves,” “electricity,” “image of light” (5:12). Grey dot again (5:35). Man appears on TV, then moves, juggling ball, racket, plate on stage (5:39). Words appear explaining how reading is good analogy for transmission of moving pictures (5:51). TV camera tube diagram, this time transmitting actual image (6:05). “Deflecting coils” (6:11). Electron beam moves across plate line by line. Sync generator with electrical pulse constituting “video signal” (6:53). On tube receiver diagram, electron beam sweeps across screen systematically, producing image (7:08). Camera tube / receiver tube diagrams shown side by side with electron beams moving from image / across screen in sync (7:37). Image produced by interlaced scanning on actual receiver (7:55). Man shown juggling while narrator explains that sound comes from FM radio (8:00). Multiple television towers shown with clouds moving behind (8:47). Narrator explains: high frequency waves cannot move beyond horizon (reception is limited). High shot of city, panning across (8:56). Hands holding coaxial cables (to link transmitters) (9:07). Zoom: wire / tube arrangement. Relay station in field. Horn-shaped antennas (to boost signal) (9:15). Man juggling again (9:33). Family in sitting room watching TV (9:43). Men at switchboard (9:57). In family room (living room), shot slowly zooms on man juggling on TV. Narrator emphasizes vocational opportunities in television (10:04). Words “the end” framed by TV screen (10:18).

This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit http://www.PeriscopeFilm.com