35-Mm and 16-Mm Portable Sound-Recording System

A new low-cost portable sound-recording system suitable for recording a standard variable-density sound track on 35-mm or 16-mm film in synchronism with a motion picture film is described. The basic system includes a two-channel mixer, a main amplifier including associated noise-reduction circuits, a compact recorder, and a power unit for operating the entire system from a 115-volt, alternating-current supply. An optional inverter providing for operation from 96-volt batteries and an alternating-and direct-current multiduty motor-control unit are also available. The various circuit facilities and the performance of the components and system with respect to sensitivity, signal-to-noise ratio, harmonic distortion, and flutter are discussed in detail. The mechanical and electrical design of the equipment make possible a high-quality sound product for both speech and music recordings, the performance specifications being consistent with the requirements and standards of major Hollywood studios.

Print ISSN

0097-5834

Published

1949-08

Content type

Original Research

DOI

10.5594/J16515