If you have a 50uH LISN, then isn't your load impedance already less than 50 ohms at 150kHz? And that reactance appears in parallel with the load impedance of the EMI receiver input. _______________________________________ _____________________________________________
Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | *** Please consider the environment before printing this e-mail From: "ce-test, qualified testing bv - Gert Gremmen" <[email protected]> To: <[email protected]>, "IEEE EMC & SAFETY PSTC" <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: 11/10/2009 10:32 PM Subject: RE: AC or DC coupling in emissions measurement Sent by: [email protected] ________________________________ >One could easily "calibrate out" this kind of response in software. No you should never do that, as the input impedance will not be 50 Ohm anymore, and the 50 Ohm is part of the measurement system. Gert Gremmen Ce-test, qualified testing bv Van: [email protected] [mailto:[email protected] <mailto:[email protected]> ] Namens Cortland Richmond Verzonden: woensdag 11 november 2009 3:11 Aan: IEEE EMC & SAFETY PSTC Onderwerp: RE: AC or DC coupling in emissions measurement Gordon, It would appear the AC coupling capacitor which has impedance enough at 150 KHz to cause 3 dB loss in the 50 Ohm circuit, but also that it's low enough R&S can warrant the receiver to meet published specs above 1 MHz. What does CISPR-16 say? Does a receiver have to be flat all the way down? One could easily "calibrate out" this kind of response in software. Regards, Cortland Richmond > [Original Message] > From: Gordon,Ian <[email protected]> > > I accept that the instrument works this way but what do the standards > require? > > > Ian Gordon - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc <http://www.ieeecommunities.org/emc-pstc> Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.html> List rules: http://www.ieee-pses.org/listrules.html <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]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc <http://www.ieeecommunities.org/emc-pstc> Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.html> List rules: http://www.ieee-pses.org/listrules.html <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]> ________________________________________________________________________ This email has been scanned for SPAM content and Viruses by the MessageL abs Email Security System. ________________________________________________________________________ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ 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]>
