Identifying 450 mc interference using a tunable receiver and a panadaptor

Many mobile systems operating in the 450-470 mc. band are troubled by radio interference. Much of this interference is caused by intermodulation and spurious radiation from other systems operating in the same geographical area and frequency band. Due to the nature of intermodulation and spurious radiation interference, any intelligence originating from the interfering stations is obscured. This makes it impossible to identify them. If the stations causing the interference cannot be identified, it is difficult to take steps to eliminate the interference. This paper describes how a 450-470 mc. tunable receiver and Panadaptor can be used to identify interference. By scanning the band visually and aurally in 200 kc steps, the fundamental frequencies of the interfering stations can be found. Knowing these frequencies, the stations can be identified.