Measurement and analysis on the radiated emission below 30 MHz from the plasma TV sets

Most CISPR standards establish the limits and measurement methods to restrict the electromagnetic emission from an electric and electronic equipment and to protect the existing radio services. In general, the frequency band for the conducted emission is from 150 kHz to 30 MHz and for the radiated emission above 30 MHz. Recently, large sized TV receivers such as plasma TV or LCD TV are getting popular. It was reported in the recent CISPR meeting that “some radio amateurs were disturbed from a plasma TV sets in Germany and the case was satisfied with conducted emission limits of relevant standard but there is no limits for radiation in the frequency range, neither electric field nor magnetic field and also no measurement methods”. In this paper, the two methods for the magnetic field measurement below 30 MHz introduced from CISPR 16-1-4, CISPR 11 and CISPR 15. Radiated magnetic field emissions from a plasma TV set were measured and compared between two methods. It was also investigated the emission characteristics of plasma TV-sets below 30 MHz. This will be used to investigate actual interference level from the plasma TV sets to the radio services.