A German acquaintance of mine calls them EMC vitamins. Best regards,
Ron Pickard -----Original Message----- From: Bob LaFrance [mailto:b...@creare.com] Sent: Thursday, March 05, 2015 7:09 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Ferrite Cores on cables and possible reduction I met an engineer who called them prayer beads. Put them on and pray they work. -----Original Message----- From: CR [mailto:k...@earthlink.net] Sent: Thursday, March 05, 2015 6:36 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Ferrite Cores on cables and possible reduction On 3/3/2015 12:38 PM, Grasso, Charles wrote: > It is generally reported (at least as far as I can remember) that a > ferrite bead clamped on a cable will provide - typically- only about > 3db of improvement as a general rule. I am now in a position Ohboy! Open that can barrel of worms, will you? My experience, when constrained to ferrites by penny-pinching and very unrealistic program managers (who regretted it later) is that _of course_ it's not that simple. On any long enough cable, one can achieve anywhere between NO attenuation and quite a bit more than 3 dB; material permitting, sometimes significantly more, depending on the ferrite characteristics and position along the cable, where the ferrite is, in that case, amismatch on a transmission line. In my opinion and (despite my unofficial motto, "take Two ferrites and call me in the morning") ferrites are the WORST Bandaid(tm). And they break too easily. Cortland Richmond - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
