Yes, I agree with a 3dB margin but I always tell my Design Engineer friends that I want a 3dB minimum margin PK (not QPk).
Kind Regards Alex McNeil Principal Engineer Tel: +44 (0)131 479 8375 Fax: +44 (0)131 479 8321 email: [email protected] -----Original Message----- From: John Barnes [mailto:[email protected]] Sent: Thursday, February 28, 2002 12:39 PM To: [email protected] Subject: Re: EMC Emissions Safety Margins Russell, At IBM and Lexmark, our EMC department was comfortable if one unit showed at least a 3dB margin between the measured emissions and the specified test limits. If we were a little closer than that, and unable to improve the margin for whatever reason, they would have us test two more units. Then if all three units had over 1.5dB margin they would pass us, but might require us to retest production units quarterly or after every significant hardware/software-design change. They also asked us to be up-front with them, and to show them our pre-approval runs to prove that these measured emission peaks did not change much run-to-run. John Barnes dBi Corporation ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
