Hi William, This is a dynamic quantity dependent on the size of the wire, number of twists, and frequency range of interest. You can get a lot of good information from the web pages of various twisted pair cable manufacturers. The normal impedance for twisted pair sold as CAT 3 and CAT 5 (and others) is 100 ohms for a given frequency range, 1-16 MHz for CAT3 and 1-100MHz for CAT5. There are others available (E1 telephony @ 120 ohms.) New flavors of twisted pair are extending the frequency range up to 350MHz. If you have access to a network analyzer, you can probably characterize a given twist/inch of xxASG wire for your frequency range of interest. Hope this helps, Dave Spencer Oresis Communications
-----Original Message----- From: William D'Orazio [mailto:dora...@cae.ca] Sent: Thursday, January 11, 2001 6:49 AM To: EMC Posting (E-mail) Subject: Zo Does anybody know the characteristic impedance of a twisted pair? Thanks in advance, <<...OLE_Obj...>> William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
