Brian- I've had a lot of success with the Agilent line of TDRs. The latest box is their Digital Communications Analyzer, Infiniium scope with differential TDR plug in. I've written a number of papers on what differential impedance means and how to interpret the measurements from a TDR to extract the differential impedance. They are posted on our web site, www.gigatest.com , in the app notes section, and are available for free download. Please help yourself. My next public signal integrity course in May, covers differential impedance. --eric ************************************** Eric Bogatin CTO, Giga Test Labs v: 913-393-1305 f: 913-393-1306 e: [log in to unmask] corporate office: 408-524-2700 134 S. Wolfe Rd Sunnyvale, CA 94086 web: www.gigatest.com <http://www.gigatest.com> ************************************** -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Brian Vascukynas Sent: Thursday, April 05, 2001 7:47 AM To: [log in to unmask] Subject: [TN] TDR Tester for Differential Impedance Measurements We are in the process of evaluating different manufacturers equipment that will perform the above measurements. So far the units that we have reviewed were a bit excessive for our needs. We currently have a Tektronic Model 1502C which we are using for controlled impedance measurements and like how this unit operates (user friendly). We are hoping to find a piece of equipment that performs differential impedance measurements that is equally easy to use and are curious on what other shops are using and/or what they may reccomend. Any suggestions ? ----------------------------------------------------------------- ---------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------------------- ---------------- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------