Investigation related to the influence of electric contact discharge on up-frequency band of CATV Internet

摘要

The internet communication by the use of CATV-network is increasing rapidly at mansions, high-rise apartments, etc., recently. The up frequency band of CATV internet communication is from 10 to 55MHz. There are some reports which the noises occur from electrical apparatuses related to television, television-game-set, etc.. and then their noises are mixed in the up frequency band. As the results, it has been reported to reduce a quality of CATV internet communication. On the other hand, although it is considered that the noises occur from electrical-apparatuses such as fluorescent-lamps, vacuum cleaners, etc. in the houses and then their noises will be mixed more or less in up frequency band, the reports related to those facts are a few. Thus, with respect to only the noises of fluorescent-lamps, switching electric contacts and small-type motors, we investigate their frequency spectrum and their reason for noise occurring on the based of the reported literatures.