Hi Dennis, If the manufacturer choose to to use ferrites to solves the emissions problem, the implementation seems clear. Inconvenient, but clear.
What if the company found HDMI cables without ferrites that solved the emissions problem, like cables from vendors that properly terminate the shields to the connectors. Is a quality cable considered 'special', and need to be shipped with products? Or does the issue fall into the category of using 'golden components' for compliance testing -- the manufacturer keeps a set of good HDMI cables for compliance testing, but doesn't ship cables with the product. I'm reminded of discussions on the listserver about selecting a brand of PC for peripheral testing, or having a particular PC with all the screws tightened and shielding contact surfaces polished clean. Pat Lawler plawl...@gmail.com On Mon, Sep 8, 2014 at 7:47 AM, dward <dw...@pctestlab.com> wrote: > Since it is the ferrite that is the ‘special accessory’, the company > would not necessarily need to provide the cable, they would only have to > provide the special accessory ferrite that would fit on the cable. Or they > would provide a means of obtaining the ferrite at the time of purchase for > the cable. Since ferrites are not typically over the counter easily > accessible accessories that would also mean that most likely the actual > ferrites would have to be provided along with instructions on how to > install them on any cable the user purchases. It does not matter if the > customer purchased the cable at a later date, that is up to them, but what > does matter is that the ferrites are dealt with AT THE TIME OF PURCHASE. > > Thanks > > > > > > Dennis Ward > > This communication and its attachements contain information from PCTEST > Engineering Laboratory, Inc., and I sintended for the exclusive use of the > recipient(s) named above. It may contain information that is confidential > and/or legally privileged. Any unauthorized use that may compromise that > confidentiality via distribution or disclosure is prohibited. Please > notify the sender immediately if you receive this communication in error, > and delete it from your computer system. Usage of PCTEST email addresses > for non-business related activities is strictly prohibited. No warranty is > made that the e-mail or attachments(s) are free from computer virus or > other defect. Thank you. > > > > *From:* Pat Lawler [mailto:plawl...@gmail.com] > *Sent:* Sunday, September 7, 2014 6:58 AM > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *Subject:* Re: [PSES] FCC EMI Test and Ferrites on Cables - a conundrum > > > > All, > > > > I was looking through sales ads for electronics equipment, and saw a > Blu-Ray disc player from a major company that came with an HDMI cable. > > > > In the past, I would have just considered this a convenience to the buyer, > like including batteries for remote controls. Now, I'm wondering if the > HDMI cable had ferrites, or came from a qualified vendor list of known-good > cable manufacturers. > > > > If a company has to supply a cable to control emissions, does that fact > need to be reinforced in the user's manual? For example, 'Use only > supplied HDMI cable or equivalent', or 'Use only <company> brand products > for best performance.' > > > > Pat Lawler > > plawl...@gmail.com > > > > On Thu, Sep 4, 2014 at 9:31 AM, Gary McInturff < > gary.mcintu...@esterline.com> wrote: > > Playing the devil advocate here only because I find this interesting and > I'm not advocating anything. Heck I'm probably just arguing for argument > sake. > > If all cables are not equal as Ghery and note and the > designer/manufacturer has knowledge of that don't the cables then become > special accessories in their own right? Under 15.27 c) They would not > normally be considered special accessory items under the definition > because they can be easily purchased at a multitude of locations. > 15.27 c) Accessory items that can be readily obtained from > multiple retail outlets are NOT (my emphasis) considered to be special > accessories ... > But given the knowledge of the designer/manufacturer that cables vary in > performance and not all cables were tested the only assurance they have > that the system will perform as intended is buy telling the consumer > exactly which cable they must use buy name and brand. But if they do that > then the cable isn't "readily obtained from multiple outlets" and is now by > definition a special accessory. Paragraph 15.27 says that "The party > responsible for the equipment, as detailed in §2.909 of this chapter, shall > ensure that these special accessories are provided with the equipment" So > now must the cable be provided? > > > Gmac > > -----Original Message----- > From: Pettit, Ghery [mailto:ghery.pet...@intel.com] > Sent: Thursday, September 04, 2014 12:46 AM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] FCC EMI Test and Ferrites on Cables > > You are highly unlikely to find the ferrite prayer beads at Best Buy. If > you don't specify which ones to get you have no idea what the result will > be. I think you are correct, the beads must be shipped with the product. > The right ones, to boot. > > Now, how does the designer know that he needs ferrite beads? My > experience has been that many (most?) HDMI cables do not have their shields > terminated properly, if at all. Once the shields are terminated correctly > problems go away. Could this be a better solution? > > Ghery S. Pettit > > - > ---------------------------------------------------------------- > 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 <emcp...@radiusnorth.net> > 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) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <emcp...@radiusnorth.net> > 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 <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
