HI Ed, yep, I terminated the LISN port when I did the CP test. At 101 Amps per phase, I cant resistively load the network..... I was thinking that a network amalyser looking into the LISN port ( power disconnect outside the room ) would perhaps show something impedance wise. Facility power appears clean under no load. Cheers,
Derek. ----- Original Message ----- From: Price, Ed <mailto:[email protected]> To: Derek Walton <mailto:[email protected]> ; IEEE EMC Discussion Group <mailto:[email protected]> Sent: Wednesday, November 14, 2007 9:46 AM Subject: RE: Interaction between EUT and LISN and Wall filter Derek: Did you also replace the current probe with a 50-ohm termination, and do you then not get the hump? Next, did you try using a resistive load on the LISN's and see if the hump is there? Finally, do you still see a hump with just a resistive load and no LISN's? I would suspect either a facility power noise source or a resonance in the chamber powerline filters. Ed Price <mailto:[email protected]> [email protected] WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (FAX) Military & Avionics EMC Is Our Specialty From: [email protected] [mailto:[email protected]] On Behalf Of Derek Walton Sent: Wednesday, November 14, 2007 7:03 AM To: IEEE EMC Discussion Group Subject: Interaction between EUT and LISN and Wall filter HI All, I'm watching a MIL STD 461 test on a stand alone EUT. Between 10 kHz and 20 kHz we have developed a Hump in out profile that wasn't present at our last test lab. The hump is identical looking with a current probe on the input to and from the LISN, so I believe I'm seeing no isolation from the LISN between the EUT and room wall filter. So, I was curious if anyone has looked into the impedance of the power supply in a room from 10 kHz to say 100 kHz? I'm thinking that my EUT and the room filter may be interacting.... We have dismised other sources nearby and in the room. Thoughts anyone? Thanks, Derek Walton ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
