Projection engineering (Sept 1929-Nov 1930)

Record Details:

Title:
Projection engineering
Date:
Sept 1929-Nov 1930
Publisher:
New York : Bryan Davis Publishing Co., Inc.
Volume:
Projection engineering (Sept 1929-Nov 1930)
Leaf #:
00070
Language:
English
Collection:
Technical Journals
Format:
Periodicals
Contributor:
Library of Congress, MBRS, Moving Image Section
Sponsor:
Library of Congress, Motion Picture, Broadcasting and Recorded Sound Division
Coordinator:
Media History Digital Library
Description:
Date Added:
September 28, 2023
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Page 62 Projection Engineering, September, 1929 JANETTE Motor-Driven Speed Reducers Quiet, smooth-running machines consisting of motor and worm-gear reducer in one compact unit. Motorend frame is cast integral with the gear housing, a unique construction conducive to compactness and perfect shaft alignments. Eeductions of 20 to 1 to 50 to 1. Motor speeds 1750 or 1150. Sizes 1/30 to 1/3 H.P. Write for Bulletin SR-529 JANETTE Rotary Converter Transforms DC to AC to operate AC radios, electric talking machines, public address systems and motion picture sound equipment in DC districts. Janette Mfg. Company, Singer Bldg. 149 Broadway New York 561 W. Monroe St., Chicago Real Estate Trust Bldg. Philadelphia Speed Reducer specially designed for talking motion picture machines. Motor speed 1750 RPM; turntable speed :j3Mj RPM. MICHROPHONES Michrophone Mixing Panels, Power Supply Panels and Racks, A.C. Operated Speech Input Amplifiers, Public Address Amplifiers for Every Purpose. ELECTRO ACOUSTIC PRODUCTS CO. 55 E. Wacker Drive, CHICAGO THE ELLIS Two Button Microphone Model No. 29 The Model 29 Ellis Microphone is of the twobutton stretched diaphram carbon granule type. It renders true, natural reproduction. The carbon hiss which is characteristic of many microphones is at an exceptionally low level. Its response to all audible frequencies is uniform. This microphone has no harmonics of its own and will give no distortion. Withstands rough handling without losing its fine adjustment. Covered by a mechanical and electrical guarantee for one full year providing the unit is not mishandled and also providing that a milliameter is used in the circuit, care being taken that not more than 14 milliamperes is allowed to pass through each button. The remarkable feature of this microphone is that sufficient sensitivity is obtainable for all practical purposes with a consumption of only 5 milliamperes at 3 volts. A factor of safety is provided in allowing 10 milliamperes to be used on each button without danger of burnout. This great sensitivity is obtained without minimizing the carbon content or creating diaphram resonance. Sufficient carbon is used to insure durability. Diameter 3.4", over all thickness 1.5". Especially recommended for all broadcast station use, public address work, etc. Representatives desired for a few open territories. No. 2 'IN Nickle Finish No. 29SB Statuary Bronze Finish ' $70°° * " LIST ELLIS ELECTRICAL LABORATORY General Sales Office 333 West Madison St., CHICAGO, ILL. Telephone CENtral 0292 Television Scanning Discs Standard 12" Aluminum Disc with mounting for %" shaft either 24, 48, 60 holes on spiral each, $8.00. Steel Bushing for mounting on %" shaft each. 75c. G-10 Neon Lamp for Synchronizing Motor speed, 75c. These Discs are now being used by leading Television Developing Engineers. Special Discs made to your specifications. Standard Neon Lamp plate size 13,£" x l1/^" stands steady load of 50 milliamperes each, $8.00. ARTHUR M. POHL 3541 Michigan Ave., Detroit, Mich. PHOTO CELLS, neon lamps, special high vacuum or gas filled tubes, and noise-free liquid grid leaks, manufactured to specifications. ARGCO LABORATORIES, Inc. 150 West 22nd St. New York City INDEX TO ADVERTISERS Acme Wire Co 57 Ad. Auriema, Inc .• 5S American Transformer Co . . .Third Cover Amplion Corp., of America . Amplisound Systems, Inc 49 Amrad Corp., The 3 Arcgo Laboratories, Inc 62 B Best Manufacturing Co 8 Burt Scientific Labs. Robert C 61 C Cameron Publishing Company 6 Clarostat Mfg. Co 53 Crowe Name Plate & Mfg. Co 61 D Daven Radio Corp 60 E Electro-Acoustic Products Co 62 Elkon. Inc 51 Ellis Elec. Laboratory 62 Enterprise Optical Company Back Cover F Flechtheim & Co., Inc., A. M 59 G G-M Laboratories, Inc 60 General Amplifier Co 64 I Int'l. Resistance Co 5 J Janette Mfg. Co 62 Jenkins & Adair, Inc 58 L Lynch Mfg. Co., Inc 59 M Miles Manufacturing Corp 60 Perryman Elec. Co 57 Pohl, Arthur M 62 Polymet Mfg. Corp 61 Projectionist Sound Institute 63 R The Rola Company 58 S Shure Brothers Co 59 Shakeproof Lock Washer Co 64 Standard Pressed Steel Co 57 TJ Universal Microphone Co 58 W Ward Leonard Elec. Co. . . .Second Cover Z Zapon Co., The 7