Hi Bob: The 120 ohm resistor you mention is typically placed across the line on the transceiver chip side of the isolation transformer. While you might be able to get away with putting it on the line side, I do not see how this would provide any protection. There is a big difference between putting the resistor across tip/ring (as you have suggested) and placing it in series with tip/ring. This particular resistor, which establishes the AC impedance presented to the incoming E1 signals, can not be placed in series with the line.
Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
