Hi! In our previous T1/T3 designs we have used line widths of 12mils for signals from the connector to the magnetic i.e. line side of the transformer. I asked why 12mil line width and my colleagues mentioned that this is to meet immunity requirements. I asked our EMC engineer and he did not see a reason for 12mil line width. So, it would be nice if somebody could shed light on this requirement. Thanks a lot in advance. Bob P.S I wanted to STOP for a moment and say that " SI-List has been very helpful and educational in shaping my career as an SI Engineer. I am grateful and indepted to all the people who post questions and to those who try to answer them. --------------------------------- Do You Yahoo!? Send FREE video emails in Yahoo! Mail. ------------------------------------------------------------------ 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 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