Radio Interference-Investigation, Suppression, and Control

The work of the Radio Division of the Department of Transport in investigating and controlling radio interference is described. A detailed description is given of the equipment in the experimental car, which is used for special investigations and measurements of signal strength and interference in the field. Thirty-three investigation cars are equipped with directional receivers and experimental surge traps. Two investigators on each car tour their respective districts, locating sources of interference and recommending cures. Means of suppressing interference, generally, are outlined, including the use of capacitors, choke coils, and shielding. The particular applications of these cures are described as relating to streetcars, electromedical apparatus, and domestic and commercial electrical equipment. Reference is made to an Act of Parliament giving the Government control of the use of interfering apparatus. A summary of means of measuring interference in foreign countries and in Canada is given with special reference to the work of the International Electrotechnical Commission.