>>>scale set to LOG, <<< OOPS, that should have been LINEAR !!!! Sorry.
Bob Richards <b...@toprudder.com> wrote: Alex, It is very common that the emissions plots will be made with the RBW and VBW that you mentioned. The actual QP and AV measurements should have the instrument set with the appropriate detector and bandwidths. The RBW should always be 9kHz, and for the average measurement the VBW should be significantly lower than the pulse repetition frequency, the detector should be SAMPLE, scale set to LOG, etc. Also, the frequency span should be set to zero for a compliance measurement. I've seen commercial automated software that does a very poor job of this. Bob Richards, NCT Square D. Alex McNeil <alex.mcn...@ingenico.co.uk> wrote: Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX ---------------------------------------------------------------- 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 emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- 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 emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
