American television directory (1946)

REQUIRES VISION — First in tlie West actually to buy a television site of the height considered most ad¬ vantageous for both Television and Frequency Modulation Broadcasting. Don Lee's purchase of a site on the top of Mt. Wilson, home of the world-famous Mt. Wilson Observatory, will give KHJFM and W6XAO a transmitter height of 5,900 feet for Television and Frequency Modu¬ lation Broadcasting. No finer location could he obtained in all Southern California. DON LEE BROADCASTING 5Y E M Hold— A di rection to a cameraman, instructing him to keep his camera where it is in readiness for the next shot. Horizontal Centering control — Control employed in television to regulate the position of the picture with respect to the axis of the cathode-ray tube. Horizontal hold control — Control employed in tele¬ vision receivers for adjusting the number of lines per second to correspond with the transmitter. Iconoscope — An RCA type of television camera tube that employs a high speed electron beam. Cur¬ rently used in studio cameras. (See Mosaic.) Image dissector — See Dissector tube. Incandescents — Hot bright lights, similar to those in most home fixtures, widely used in television studios. Interlacing — A scanning process in which suc¬ cessively scanned lines are spaced an integral number of line-widths, and in which the adjacent lines are scanned during successive cycles of the field fre¬ quency scanning. Ion spot — A discoloration occurring at the center of the screen-face of a cathode-ray tube caused by heavy negative ions striking it. Formerly quite trou¬ blesome. A number of systems are now in use to trap these negative ions and prevent the formation of the ion spot. Kinescope — RCA designation for the cathode-ray tube employed in television receivers for translating electrical impulses into picture elements. Klieg light — A type of powerful incandescent lamp used for spotlighting and modeling. It is usually mounted on a mobile base. Lap dissolve — A slow dissolve between two pictures in which the two images remain superimposed on the screen for a few seconds. Line — A single strip across a picture, containing highlights, shadow and half-tone?. The path cov¬ ered by the moving electron spot in a cathode-ray tube. Variations in the intensity of this spot create portions of the picture. Present U. S. systems em¬ ploy 525 lines for a complete picture. Linearity — The uniformity of distribution of a reg¬ ular pattern on a television picture tube. Line of sight —The unobstructed path between two points. Important in high frequency radio wave transmission. Live talent — Any studio presentation in television or the people who appear in it. Distinguished from film programs. Long shot — An establishing shot taken from a di tance that is sufficient to include a complete view of the scene. Lumen — -Unit used for the measurement of light flux. One foot-candle is equal to one lumen per square foot of surface. Luminescent — Possessing the property cf producing light without the generation of heat. Megacycle — When used as a unit of frequency, I\lc stands for 1,000,000 cycles per second. Mercury vapor lamp — A “cold” light, coming into wide use for overhead foundation illumination in television studios. Electric current vaporizes mer-ury in a water-cooled tube, thus producing light without much heat. Microphone — A sensitive device used for converting sound waves into electrical impulses of varying cur¬ rent and transmitting them. Microphone boom — A device, usually in the form of an adjustable crane, for suspending the micro¬ phone used in television above the area being tele¬ vised. Microwaves — Radio waves of extremely high fre¬ quencies, having wave-lengths of less than one meter, or greater than 300 megacycles. Medium shot — A shot taken from middle distance, or from knee level to above the head of the subject. Modulation — A process in which the character of the carrier wave may be varied in frequency, phase or amplitude in accordance with the information to be transmitted. Monitor — Any receiver or speaker on the strtion circuit on which the quality of the program or rehearsal can be watched or heard. Monitoring — The technique of controlling the trans¬ mission of the picture or sound tied in radio, tele¬ vision and motion picture work. Monoscope — A special cathode-ray tube that is de¬ signed to produce a single siationary picture pat¬ tern useful in testing or adjusting television equip¬ ment. Montage — See Superimposure. Mosaic — The photo-semi i.e screen mounted In an Iconoscope. The picture is optically focussed upon the mosaic and then scanned by the electron beam from the election gun. So named because of its similarity to that form of art in which many bits cf tile are combined to form a picture. Mn! lip-avis tra:o:rsia:io:i — A condition wherein the radio signal from a transmitter t ravel s to the re¬ ceiver by m )ie than one route. Usually re ults in reflections and usually causes ghost images on re¬ ceiver screen. NegaU'/c ghosts — Cho-t images in which the black and white areas are reversed. 0:;-scrs3n voice — The voice of a pc—on not ap¬ pearing in the television picture. Used for narra¬ tion, announcements, etc. Orthicon— A camera tube that utilizes a low-meed electron beam. Superior in sensitivity to the Icono¬ scope but inferior to it in resolution. Usually em¬ ployed in field cameras for out-of-doors televising. Oscillograph or Oscilloscope — An apparatus that produces a continuous curve to represent the values of a varying electrical quantity. Used as a test instrument to show the wave form of any varying voltage or current. Panning — (From “panorama”). A horizontal sweep of the camera. A camera technique in which a large arc of the scene is shown by turning the camera without changing its position. 113