John, I am looking for the actual data supporting the chosen LCL characteristics for the CAT5, 6 and 7 ISN per the standard. According to the described intent of the standard, the ISN characteristics are such to purposely introduce imbalance, supposedly to replicate the LCL characteristics of a "typical" network installation, but I do not find any published data on the LCL of the "typical" CAT5, 6, and 7 installations. The method of the measuremtn is described in ITU-T G.117 standard. I hope that there is a considerable work somewhere available that supports the chosen CAT5, 6, and 7 LCL characteristics, but I also fear that the information is not available, and I believe it should certainly be available for a standard with such a broad consequence for the industry. My back-of-the-envelope calculation tells me that 10 BaseT Ethernet, with maximum 5.6Vpk-pk amplitude, as defined per IEEE 802.3 standard is most likely to fail ClassB limit with the CAT5 LCL as defined by CISPR22, 2005. Most manufacturers do not generate as high voltage, but it is possible per the IEEE Ethernet standard. Laptop/PC and other SOHO Ethernet-product manufacturers are going to have hell of a time trying to make it through. Regards, Neven
-------------- Original message -------------- From: John Woodgate <j...@jmwa.demon.co.uk> > In message > <062020062152.8474.44986E2800008DE20000211A2205886442CECE020A900A02@comca > st.net>, dated Tue, 20 Jun 2006, neve...@comcast.net writes > > >Does anyone have or know the sources (preferably published, verifiable, > >with the exact test method described) of the LCL (Longitudinal > >Conversion Loss, i.e. balance) of "typical installation" that support > >the LCL values required by CSPR22 for ISN for CAT5, 6, and 7 cables? > >(CISPR22 5th edition, 2005, page 51) > > Are you looking for a method of testing the actual cables for unbalance? > > I think you need to look at IEC standards in the IEC 61156 series, at: > > http://tinyurl.com/zarag > > If you click on the standard number, you get a detailed page about it, > and if you click on the 'Preview' icon you get the Table of contents, > the Scope clause and a few more pages of the standard to view for free. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > 2006 is YMMVI- Your mileage may vary immensely. > > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- 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/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 Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
