International projectionist (Jan 1963-June 1965)

How electrical noise is produced . . . calculated . . . measured . . . controlled Here are the basic facts about electrical noise — how it originates in circuits . . . what terms describe it . . . how to measure it . . . how to design circuits to minimize its undesirable effects. The physical nature of the various sources of noise are clearly described, including such sources as thermal agitation or resistance noise . . . shot noise in vacuum tubes and semiconductor junctions . . . noise from spontaneous emission of electromagnetic radiation . . . and noise in gas discharges. This practical book also explains auxiliary mathematical techniques, and discusses the relation of signal and noise in various types of communication systems. For ease in use, the simple tuned circuit associated with a device for measuring average power is made the basic tool for analyzing ELECTRICAL 270 pages, 6x9 105 illustration* $10.00 By WILLIAM R. BENNETT Data Communications Consultant, Bell Telephone Laboratories, Inc. Each chapter in this helpful book begins in a simple, practical manner and works toward more complicated examples. For example, properties of thermal noise and its relation to blackbody radiation are deduced from basic laws of thermodynamics and statistical mechanics. You also will find a clear treatment of elementary quantum mechanics in discussions of the maser and of noise in semiconductors. And, in describing noise properties of various devices, the book fills in your working background with basic facts on junction diodes — transistors — gas discharge tubes— klystrons— traveling wave amplifiers— and others. Both independent and dependent noise sources are analyzed. In addition to the standard theory of noise figure and its significance, a treatment is given of the more comprehensive Haus-Adler theory of noise measure. Throughout, the book stresses the universality of noise-like phenomena. Noise formulas for diodes and transistors; noise generation to meet specifications; design of amplifiers for minimum noise effects— these and many other topics "are covered. A comprehensive review of noise in the various methods of signal transmission such as amplitude modulation . . . frequency modulation . . . and the different lands of pulse modulation is included. CONTENTS 1. General Properties of Noise 2. Thermal Noise 3. Distribution of Magnitudes in Noise Sources 4. Noise in Vacuum Tubes 5. Noise in Semiconductors 6. Noise in Electromagnetic Radiation 7. Noise-generating Equipment 8. Noise Measurements and Techniques 9. Design of Low-noise Equipment 10. Application of Fourier Analysis to Noise Problems 11. Noise in Communication Systems INTERNATIONAL PROJECTIONIST Post Office Box 6174 Minneapolis 24, Minnesota Please send me a copy of "Electrical Noise" by William R. Bennett. (I enclose $10.00.) Name Address City & State INTERNATIONAL PROJECTIONIST Post Office Box 6174 Minneapolis 24, Minnesota □ 1 year (12) issues — $3.00 □ 2 years (24) issues — $5.00 FOREIGN: Add $1.00 per year Enter my subscription for Name Address City Zone State black and white projection as well as color, it is claimed. Light output from the projector is more than 3750 lumens. This is adequate for all types of theatre screens up to 25 ft. in height and 33 ft. wide, including drive-in theatres. With proper lens attachments the throwdistance-to-picture-height ratio changes from 3.1:1 to 10:1, which covers nearly all theatres. The Talaria system is capable of producing a wider gamut of colors than the best color film available it is claimed, because color is determined by optical filters rather than dyes. Resolution, or amount of detail, is about 500 TV lines, better than home TV receivers. Uniformity of illumination is excellent. Illumination at the edges of the Talaria picture falls to 70% of that at the center. ( SMPTE standards allow a drop to 60%). The Talaria projector is designed to operate with the FCC-approved color system which encodes color on a 3.58-megacycle chrominance subcarrier. The FCC system uses a bandwidth of 4.5 megacycles, but the new projector can also work on a wideband 7-megacycle system with a 6.44 megacycle subcarrier. Overall length of the projector is 5 ft., 8 in.; height 5 ft., 4 in.; width, 2 ft.. 5 in. Weight is approximately 1.000 lbs. The projector can be disassembled into two units for portability. iP 18 CINERAMA from Page 15 over a much larger structural area, which contributes to the resistance of the loads. Because the shortest distance between two points on a sphere is an arc of a great circle (called a geodesic I all of the force lines of the dome lie along great circles. This arrangement results in an equal distribution of stresses in all directions, balancing tension against compression. It also makes possible the use of lightweight materials which in conventional structures would hardly be able to support their own weight. The dome can cover a large area without requiring support braces and trusses normally used in construction. Instead, its structure and skin are one. It is made by piecing together diamond-shaped panels of concrete, plastic, aluminum, or other material. Each panel has turned-up edges, like the rim of a pie pan. The dome is assembled simply by bolting together the rims of adjoining panels. iP International Projectionist March 1963