To all, QP detection of the pulse requires a linear detector. The spectrum anlayzer should be set up with uV (rather than dBuV) on the vertical scale. Let me know if the RC time constant displays differently with the new setting (there may be some dynamic range issues so some experimenting may be required).
Regards, Kurt Fischer >Date: Mon, 19 Apr 2004 15:29:35 -0600 >From: drcuthb...@micron.com >Subject: RE: Calculating/predicting Quasi-peak of a single pulse >To: <drew.rosenb...@itron.com>, <emc-p...@majordomo.ieee.org> > > >Drew, > >What have you got the RBW and VBW set to? > > Dave Cuthbert > Micron Technology > >-----Original Message----- >From: owner-emc-p...@majordomo.ieee.org >[mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Rosenberg, Drew >Sent: Monday, April 19, 2004 3:00 PM >To: emc-p...@majordomo.ieee.org >Subject: Calculating/predicting Quasi-peak of a single pulse > > > >Hi EMC Gurus, > I have been struggling with something for a while and have >decided that this is the best place to send my question: > > I would like to better understand how quasi-peak is determined >on a single pulse of specified duration. From my understanding, >Quasi-peak applies an RC time constant to the pulse. If the pulse >length equals 5 times the RC time constant, then the QP measurement will >be roughly 99% of the peak measurement. > According to CISPR-16-1 Table 1, the charging time constant >specified is 1 ms. Therefore, according to my understanding, QP should >be 99% of peak measurement at 5ms. > > However, my experiments have given very different results. I >have an HP8593E spectrum analyzer. In an effort to prove my >understanding of CISPR-16-1's definition of Quasi-peak, I applied a 1 >second 900 MHz pulse to the spectrum analyzer with QP detection on. >This 1 second pulse was applied using the pulse trigger of a Marconi >2024 sig gen. To my surprise, QP did not equal peak until about 500ms. > > Does anyone know why I am getting such different results than >what I had predicted? > > I have data and analyzer pics if anyone thinks that they would >help. I have been told that attachments are not good for list servers, >so please let me know if you would like to see them. > >Regards, > >Drew Rosenberg >Regulatory Engineer >Itron, Inc. >2401 North State Street >PO Box 1735 >Waseca, MN 56093 >Tel 507-837-5264 >Fax 507-837-5200 >drew.rosenb...@itron.com > > > > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ieee-pses.org/ > >To cancel your subscription, send mail to: > majord...@ieee.org >with the single line: > unsubscribe emc-pstc > >For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: emc_p...@symbol.com > >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 EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ieee-pses.org/ > >To cancel your subscription, send mail to: > majord...@ieee.org >with the single line: > unsubscribe emc-pstc > >For help, send mail to the list administrators: > Ron Pickard: emc-p...@hypercom.com > Dave Heald: emc_p...@symbol.com > >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 EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com 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
