... made up with special materials and are immersed in lacquer by peculiar tech. Vanish and colophony materials are develop to ... distortion and output voltage.Phone interferenceTHF(defined by 40th part of BS4999) <2%.TIF(defined by ASAC50.12)<50Radio interferenceBrushless apparatus and ... not include in the quality guarantee.Manufacturing StandardsGB755, Third part of BS 5000,VDE 0530, NEMA MG1-22,IEC34, ...