Courtland Whether CISPR-16 says that the response should be flat or not was the purpose of my question. Unfortunately CISPR-16 doesn't make very easy reading! That was why I asked this question of the group. When doing product testing at these low frequencies a reduction of up to 20dB in indicated level between AC and DC coupled inputs was seen. I think it's reasonable to expect a calibrated reference source to produce a corresponding indicated signal level in a measurement device and thus I need to use DC coupling for my R&S receiver at these lower frequencies. However I need to ensure that the input is protected against overload. I also need a driver for the R&S ESCI 7 that will work with the Teseq C3 emissions software and "force" the receiver to use DC coupling. Any offers?
Ian Gordon From: [email protected] [mailto:[email protected]] On Behalf Of Cortland Richmond Sent: 11 November 2009 02:11 To: IEEE EMC & SAFETY PSTC Subject: 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 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]> --- --- --- --- --- --- --- --- --- --- --- --- --- The contents of this email and any attachments are confidential and are provided solely for the use of the intended recipient(s). If you are not the intended recipient, you are hereby notified that any copying, disclosure, distribution, or use of this e-mail, its attachments or any information contained therein is unauthorized and strictly prohibited and you should please contact the sender immediately and delete this e-mail and any attachments from your system. No responsibility is accepted for any virus or defect that might arise from opening this e-mail or attachments, whether or not it has been checked by anti-virus software. - 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]>
