A COMMUNICATIONS TRANSMISSION SYSTEM INCLUDING FACILITIES FOR SUPRESSING ELECTROMAGNETIC INTERFERENCE

摘要

A balanced mode transmission system (20) for use in a local area network includes at least one twisted pair of insulated metallic conductors (27-27) which at its end is connected through a transformer to a transmitting computer and to a receiving computer (48). Each pair adjacent to the transmitting end and optionally to the receiving end is provided with a longitudinal choke (56,57). Also, a longitudinally extending metallic wire (60) is included in the system and is connected possibly through a resistor to ground at each end. The combination of the longitudinal choke at least adjacent to the transmitting end and the longitudinally extending metallic wire is superbly effective in suppressing electromagnetic interference notwithstanding the absence of shielding.