Radio-Interference Control as Applied to Business Machines

This paper discusses certain known characteristics and sources of radio interference and methods used to reduce the interference levels present in business machines. Particular attention is given to electro-mechanical machines ranging from a simple card perforator, operated by an electrical contact and an electromagnet, to electronic data-processing machines. The sources of interference in these machines are found in a wide variety of components and circuit configurations, such as electrical contacts, gas tubes, unterminated transmission lines and motors.