International projectionist (Jan-Dec 1950)

applications indicated by patent disclosures listed in the bibliography. Measuring and Testing Equipment This is the third and most important group of uses, and it is of primary interest to us since its use in the cathode-ray oscilloscope is included. In this capacity, it performs two major roles. The foremost is its function as the display element. Information made available by the unit appears on the screen of the tube. The interpretation of this information in volves the proper correlation of the trace with the settings of the auxiliary apparatus, which, together with the tube, comprises the oscilloscope. Sometimes the complete device is housed in one metal cabinet. At other times, accessory apparatus is used with it, and the complete system then consists of several individual units. Even then, the cathode-ray oscilloscope is a complete individual assembly. The second major role of the tube is related to its practical purpose. Its purpose is to portray one voltage as a function of another. In general, where the cathode-ray tube is used for instrumentation purposes, electrostatic-deflection look to WENZEL for the Finest in Projector Equipment I Closed Sound Head WENZEL PROJECTOR CO. 2050-19 S. State St. Projector Chicago 16, III. Head BORDER TO BORDER COAST TO COAST NATIONAL YOU CAN "RELY" ON NATIONAL EFFICIENT • DEPENDABLE RECTIFIERS for Every Type Projection Lamp 2-Tube 4-Tube .. 6-Tube Single and Three Phase s Models for • Rotating Feed Angular Trim High Intensity • Copper Coated Coaxial High Intensity • 1 K.W. High Intensity • Low Intensity Smooth Output Current • Long Life Low Operating Temperature Flexibility in Control Write today for literature or free demonstration st R Otf<* t*A*cco*; IV tCT^ 31 CITY PARK AVENUE TOLEDO 2, OHIO PROJECTION LAMPS • RECTIFIERS SPOTLIGHTS • REFLECTORS Um r1 AM FIG. 4. Patterns indicating different types of waveforms, obtainable with a cathode-ray oscilloscope. methods will be used. This is so because only electrostatic-deflection methods are sufficiently versatile to perform the variety of functions, and reproduce the great variety of waveforms the oscilloscope is called upon to reproduce. Electromagnetic deflection is usually used where the conditions of operation are fixed, as, for example, in television receivers and radar receivers. Examples of patterns representative of the diversified applications of the cathoderay oscilloscope appear in Fig. 4. All of these picture electrical phenomena. This deals with fundamental electrical measurements rather than non-electrical applications. NEWS PROJECTIONS FEDERAL Court in New York has extended time for both Warner Bros, and 20th Century-Fox to file final plans for divorcement of their exhibition interests from production. Warners now has until Jan. 15. and Fox until March 5, both 1951. . . . Eastman Kodak reported net earnings of $43,134,237 for the first three quarters of this year, an increase of $9 millions over same period last year. . . . Allen B. DuMont Labs reports profits up 199% to $5,018,000, over same period of 40 weeks last year. Sales rose 77%. . . . Reaction to the Army-Navy football game telecast at six large-screen theaters in the East ranged from "excellent" to "fair," with management in every case citing a distinct improvement over usual week-end biz. . . . Technicolor will turn out 60 features during 1951, an increase of 33 1/3% over this year. . . . Detroit exhibitors approve of theater Tv, but they warn against the general tendency to over-price the shows. . . . RKO's net profit for the 39 weeks ending Sept. 30 was $608,632, which figure includes a net profit of $216,185 on the sale of capital assets. •x * * The long-delayed test of Phonevision, pay-as-you-see Tv system sponsored by 36 INTERNATIONAL PROJECTIONIST • December 1950