Did you try placing an attenuator between the LISN and the filter? 3 or 6 dB should help. Dave Cuthbert
From: [email protected] [mailto:[email protected]] On Behalf Of Donnelly, Thomas Sent: Thursday, May 06, 2004 5:15 AM To: 'Bill Stumpf'; EMC-PST (E-mail) Subject: RE: In-house LISN calibration As I understand ANSI C63.4 the impedance measurement is required. In fact it is required that you meet the curve when connected to ant EMI filters you would use during a test. At a previous employer this was interpreted as a mandate to calibrate them in house. This really created a nightmare considering that there were 6 chambers and a couple dozen different LISN's. Connecting to a filter does make a difference. In fact we had several LISN's that looked good standalone that did not meet the criteria when connected to the filter. We wound up tuning the LISN's to meet the curve with the filters attached. Anyone else run into this problem? Tom Donnelly Smiths Aerospace Actuation Systems 973-428-9898 x445 [email protected] From: Bill Stumpf [mailto:[email protected]] Sent: Wednesday, May 05, 2004 2:50 PM To: '[email protected]'; [email protected] Subject: RE: In-house LISN calibration Tim, The standard to be used for LISN calibration is ANSI C63.4. The insertion loss can be measured using a spectrum analyzer, but I am not aware of a method to use a spectrum analyzer for the impedance. We use a S-Parameters Network Analyzer. Bill -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Wednesday, May 05, 2004 12:15 PM To: [email protected] Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
