Tom As Russell has stated, there is pretty much no way to create a twisted pair model from EM field solvers that will correlate with measurement. There are so many variations in the manufacture of cable and repetitive variations due to the process, that it truly takes measurement to determine the actual cable behavior. in our work we have used VNA and TDR measurment based modeling approaches to create cable models. I would suggest an approach using a TDR and TDA Systems iConnect, or an approach using a VNA with a sweep range from the 100 kHz to 1 GHz range and s-parameter modeling. (HSPICE now does a reasonably good job of using Touchstone S-parameters in time domain simulation ... although it is slow) regards, scott -- Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax (503) 750-6481 Cellular http://www.teraspeed.com Teraspeed is the registered service mark of Teraspeed Consulting Group LLC ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu