The motion picture projectionist (Nov 1931-Jan 1933)

Motion Picture Projectionist November, 1931 Report of S. M. P. E. Progress Committee (Continued from page 28) drives the receiving scanning disc. A 3-watt neon lamp is used for a picture area of 600 sq. cm. as opposed to a 250-watt lamp for a 6 sq. cm. area in certain other systems. General Recording. — Stroboscopic motion pictures of the angular transients of synchronous motors have been taken by Edgerton with the aid of a mercury arc thyratron. Possible applications are the study of the claw mechanisms of high speed cameras and projectors or the valve spring action of gas engines. THEATREiJCQUIPMCNT Cfr /^». NEW AND USED 1 Sound Equipment, Moving . Picture Machines, Screens, Booths, Opera Chairs, Spotlights, Sterk eopticons, Film Cabinets, ? Portable Projectors, M. nP.: Cameras, Generator S e t s , Reflecting Arc ^ Lamps, Carbons, Tickets, plies. Projection Machines repaired and overhauled. Repair parts for all makes opera chairs. Attractive 3 x 10 ft. muslin banners, $1.50 ; on paper, 50 cents. We Pay Highest Prices for Used Projection Machines, Opera Chairs, etc. Ercrytbini for the Theatre— Writ* (or Catalog K. tVOVIE SUPPLY CO.. 144 So. Wibaih. ChicaMZ If you haven't Proper Projection ? STRONG g^High Intensity Automatic ' -4j Reflector Arc Lamp Eliminates the troublesome relay arc control, is economical of current and carbon, ball bearing arc control feeds the carbons continuously as consumed, accommodates full 8-inch trim without resetting carbon, has widely spaced bearings which assure perfect alignment throughout entire trim. FOR SALE BY INDEPENDENT SUPPLY DEALERS £he Strong Electric Corporation 2501 LAGRANGE ST. TOLEDO, OHIO Export Office: 44 Whitehall St., New York City, N. Y. Just Published! the key to better sound projection HERE is the clear, simple explanation o f sound equipment, its operation and repair, needed by all projectionists. Gives the fundamental principles on which all makes of equipment are based. Explains their use so that you can recognize the nature of any sound trouble, trace it to its cause, diagnose its importance, take the right steps to correct it. Shows when and how repairs can be made in a hurry — when replacement of parts is necessary. Shows how to keep your show running, with sound of the best quality. Proj ecting Sound Pictures By AARON NADELL Publix Theatres Corporation ; Formerly of Electrical Research Products, Inc. 265 pages, 6x9, 100 illustrations, $2.50. Everything in this book is practical and explained in understandable language. Instead of describing all makes of sound equipment in detail, the author clearly outlines the fundamentals of mechanisms and circuits found in all sound apparatus, and which, when understood, make easy the location and cure of all sound troubles. Covers theory and mechanical requirements of sound-on-film and sound-ondisc — projectors, amplifiers, rectifiers, loud speakers, motors, generators — their principles, operation, maintainence — photo-electric cells, vacuum tube* and circuits — acoustics — care of sound equipment and precautions to prevent trouble — tracing trouble See this book for 10 days FREE Send this coupon today 1 I I McGraw-Hill Book Co., Inc., 370 Seventh Ave., N. Y. City. Send me Nadell-Projecting Sound I Pictures, postpaid for ten diys' free examination. I will send $2.50 or return the book within ten days of receipt. I Name I Address City and State Position Company M.P.-11-81 Sell Portable Talkie Sound-on Film to Theatres, Schools, Churches, Clubs, etc. Write for manufacturers' prices on Soundheads, Photocells, Optical Systems, Rectifiers, Amplifiers, Horns, Faders, Synchronous Motors, Projectors, Lamphouses, Screens, Microphones, etc. S. O. S. Corporation Dept. M. P., 1600 Broadway, New York City Cable Address, "SOSOUND"