Problems, methods, and achievements in conforming to standards for vehicular radio frequency interference

Increased usage of the Land Mobile Service, increasing sensitivity of receivers, and greater demands on communication systems are causing attention to be directed toward interference radiated from automotive ignition systems. Although U.S. vehicles are presently designed to limit radiation, lack of uniformity exists between standards in North America and Europe resulting in duplication of test work. The United States automotive industry is cooperating in the development of a world-wide standard using a unique sampling procedure, and has used new computer techniques to derive a greater amount of information from data available. Revisions now under way in the U.S. industry Standard will provide procedures and limits to 1000 MHz, will protect all present TV bands, and will make our standards compatible with Common Market usage. Theoretical studies and testing show that vehicular radiation decreases above 400 MHz and that existing techniques may prove satisfactory. Joint studies of an FCC-industry group are expected to develop additional information.