Absolutely correct. I ASSUMED that what was meant was that shielding the cable resulted in no better than a 6 dB reduction in cable-sourced emissions. Something you could check with a current probe. If an entire system is being tested then clearly other emission sources could mask any cable-sourced improvements.
Ken Javor on 2/24/03 11:04 AM, drcuthbert at drcuthb...@micron.com wrote: > The fact that going from unshielded to shielded cable cut emissions by 6 dB > does not necessarily mean that the shield cut cable emissions by only 6 dB. It > could mean that the cable emissions have been greatly reduced but another part > of the system has emissions that are 6 dB below the original configuration. > Like pealing an onion and revealing the layers of EMI. > > Dave Cuthbert > Micron Technology > > -----Original Message----- > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Monday, February 24, 2003 7:22 AM > To: Jan Vercammen; emc-p...@majordomo.ieee.org > Subject: Re: Shieled ethernet cables in Germany > > > > To Jan Vercammen and Michael Nagel and the whole forum, > > If a decent shield only provides 6 dB of shielding effectiveness at best, > that is an indictment of the termination impedance(s) and Doug Smith is > right, other techniques need to be investigated for reducing emissions and > immunity. > > Ken Javor > > -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
