International projectionist (Jan-Dec 1946)

SOUND-REPRODUCING UNITS [Continued from page 12 1 they were discarded in favor of the actual gain figures listed in current bulletins. However, these earlier figures were quite suitable for field tests. To the foregoing gain figures the 60 c.p.s. correction factor should be added. In order to determine the frequency characteristics of these amplifiers, an oscillator is required. Since the gain has already been determined by practical means, the oscillator output is adjusted to 60 c.p.s. and connected to the film amplifier under test through a 10-megohm resistor. Adjust the oscillator output level until a V.I. reading similar to that obtained with the former signal source is obtained at amplifier output. Oscillator Output Level Maintain this oscillator output level at all test frequencies and note signal variations at amplifier output. These variations, when compared with the reference frequency, denote the frequency response of the amplifier under simulated normal working conditions. It will be found, providing reasonably short leads are used, that the frequency response of these amplifiers will closely follow those given in the equipment bulletins— that is, if the amplifier is all right. It may be noted, if very short leads are used and the 10-megohm resistor omitted, that these amplifiers are practically flat from 60 to 10,000 c.p.s. Tele Broadcasters' Assoc. Meet in N. Y., Oct. 10-11 Television Broadcasters Association, Inc.. has announced the Second Television Conference and Exhibition at the Waldorf-Astoria Hotel. N. Y. City, on October 10 and 11. The two-day event is open to all interested persons and will bring together persons and organizationsfrom all fields sharing interest in the progress of television. Blanket registration fee of $25 will include admittance to all general sessions and panel meetings, all exhibits, two luncheons, the banquet and cocktail party, as well as a transcript of all proceedings. Reservations may be directed to the Association at Suite 1038. 500 Fifth Ave., N. Y. City, 18. The Conference date coincides with the date announced for the introduction of major-company tele receivers, thus a fine exhibit is assured. New Bausch & Lomb Plant Increased manufacturing demands have forced Bausch & Lomb Optical Co. to acquire a new plant in Wellsville, N. Y., 90 miles south of the main plant in Rochester. Initial production schedules, utilizing principally women workers, center on light manufacturing, with 30 more workers being added each month to a total number of several hundred. % *m4 >\r LOOK AHEAD TO television! Complete Authentic Data on the Most Advanced Production Techniques Television is coming — and coming fast ! Wise operators will want to know what it is all about — and just where they might fit into this new industry that promises to revolutionize modern entertainment standards and practices! TELEVISION VERSUS THE MOVIES Let Richard Hubbell, a prominent television production manager and consultant, give you the answers: How will Television programs be prepared and handled? What are the technical problems involved? What about Television optics and methods of operation? How and to what extent will Television compete with movies? biosi important of all. his book TELEVISION PROGRAMMING AND PRODUCTION paves the way to interesting new job possibilities by acquainting you with the most advanced techniques; by discussing equipment and technical problems; and by providing a wealth of factual material never before available in handy, easily understood book form. More than 50 selected photos demonstrate specific Television productions. Easily understood drawings vividly illustrate production principles, problems and technical matters. 207 pages. Scores of illustrations, diagrams, charts, S3. IT PAYS TO KNOW RADIO -ELECTRONICS! Let A. A. Ghirardi give you a complete working knowledge of basic Radio-Electronics — for only $5 complete! His big 972page RADIO PHYSICS COURSE book provides valuable training for every projectionist who likes to know the theory and principles behind the equipment he uses. Over 300 pages are devoted to Basic Electricity without which no training of this type can hope to be complete or even understandable. From here, RADIO PHYSICS COURSE carries you through radioelectronic principles to tubes, components, circuits, radio and audio amplification — every factor on which modern RadioElectronics is based. Nothing is omitted or condensed. Everything is made crystal clear both by text and 508 illustrations. 856 self-test review questions make it easy to check your progress every step of the "'ay. Sold on our unreserved 5-DAY MONEY-BACK GUARANTEE BASIS. Ghirardi's RADIO PHYSICS COURSE offers complete basic Radio-Electronic training for beginners. More widely used for home study and for more U. S. Signal Corps and Navy training courses and for more civilian schools than any other book of its kind. FIX RADIOS FOR FUN AND PROFIT Every radio has its "weak spots" where trouble FIRST starts. Simply look up the make, model and trouble symptom of the radio you want to repair in Ghirardi's famous RADIO TROUBLESHOOTER'S HANDBOOK— and go to work. No needless, tedious testing. It tells exactly what the trouble is likely to be . . . exactly how to fix it. This 4 lb., 744-page manual-size Handtook brings you factual repair data fcr practically every radio in use today — over 4,800 makes and models. Over 300 additional pages contain repair charts, tube charts, tuning alignment data, etc., that will help you repair any radio ever made easier, better and faster. Only $5. 5 DAY MONEYBACK GUARANTEE Murray Hill Books. Inc.. Dept. IP-96. 232 Madison Ave., New York 16, N. Y. n Enclosed find S for book9 checked: or □ send C.O.D. for this amount (in U.S.A. only) plus postage. If not fully satisfied, I may return the books within 5 days for complete refund of my money. □ TELEVISION PROGRAMMING AND PRODUCTION S3 (33.25 foreign) □ Ghirardi's RADIO PHYSICS COURSE $5 (S5.50 foreign) □ Ghirardi's RADIO TROUBLESHOOTER'S HANDBOOK S5 (S5.50 foreign) Name Address CItv & Dist. No State INTERNATIONAL PROJECTIONIST • September, 1946 25