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

Want to support this channel and help us preserve old films? Visit https://www.patreon.com/PeriscopeFilm Visit our website www.PeriscopeFilm.com 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