EN 55022 DC Conducted Emissions on Car Charger
Hello Colleagues, I was recently approached regarding the testing of DC conducted emissions on a car charger for a 2 Way Portable radio and if it is required. The applicable EMC standard per the RTTE Directive would be 301 489-5, which basically falls back on 301 489-1 without any special conditions. The way I read 301 489-1 is that DC conducted emissions are to be tested per EN 55022 for AC/DC power adapters at the AC mains for equipment with DC cables or = 3m or at the DC power port if the manufacturer declares the length of the cord to be over 3m. Neither of these are true in this case, so I don't believe that DC conducted emissions are applicable. However, I have never researched this before and am open to the fact that I am missing something. The engineer has gotten information from another source stating that the charger must be tested to EN 55022 for DC conducted emissions. Does anyone out there know if this is accurate? If so, what kind of AMN would you recommend to measure DC conducted emissions? If this is the case, can you also direct me to the applicable standard that calls out EN 55022 or help me understand why it is applicable if my understanding of 301 489 is incorrect? Always learning Best regards, Mac Elliott __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ - 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
Re: EN 301 489-1 emissions question
In message 17191.81.86.19.62.1150098003.squir...@www.kcchosting.co.uk, dated Mon, 12 Jun 2006, Charles Blackham charles.black...@sulisconsultants.com writes However as Point-of-Sale equipment is not typically domestic equipment, if you can state categorically that this is the case, you could write a draft TCF and ask a Competent Body to give you an opinion to clause 3.1b of the RTTE directive. The crunch argument would be that no TV or radio receivers would be likely to be within 10 m (preferably 30 m) of the product. -- 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
RE: EN 301 489-1 emissions question
David: All: To claim compliance with EN 301489-1 (I am looking at V1.6.1), Clause 8.4.3 Limits, the way the clause is worded, your equipment is not installed in a telecommunications center as one would infer from ETSI TR 101 651. The reason for Table 9: Limits for conducted emissions of equipment intended to be used in telecommunication centres only is to be in alignment with EN 300 386, which does allow Class A conducted emissions limits, as previously discussed. It appears you will be having to comply with the Section 8.4.3; Table 8, Conducted Limits. William T. Sykes Lucent Technologies EHS Product Safety/Conformance Manager Room 7B-516A 600-700 Mountain Avenue Murray Hill, NJ 07974-0636 (908)582-6937 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of David Gelfand Sent: Friday, June 09, 2006 2:05 PM To: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question So, how about my original question? Is Class A conducted emissions ok for a tower-mount VSAT power amp? Depending on the answer, I will either enjoy a beer or have a terrible weekend. Regards, David. _ From: McInturff Gary [mailto:gmcintu...@spraycool.com] Sent: 9 juin 2006 13:27 To: Mike Hurley; David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Mike, I owe you a beer now. You just made my day. Unfortunately since we are unlikely to ever been in the same place I'm taking it upon myself to drink it for you too. I'll let you know if you enjoyed it. Thanks Gary _ From: Mike Hurley [mailto:mikehur...@meadtest.com] Sent: Fri 6/9/2006 9:38 AM To: McInturff Gary; 'David Heald'; 'David Gelfand' Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Gary, Your recollection is correct, Telecom centres were indeed Class B in Europe. It took us several years in the ETSI EE4 committee to get it changed to class A and even then it was by the somewhat devious means of removing emission limits from EN300 386 and instead referencing directly to EN55022. There are probably a few emc-pstc folk who remember the struggle. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff Gary Sent: 09 June 2006 15:50 To: David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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 - 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
RE: EN 301 489-1 emissions question
So, how about my original question? Is Class A conducted emissions ok for a tower-mount VSAT power amp? Depending on the answer, I will either enjoy a beer or have a terrible weekend. Regards, David. _ From: McInturff Gary [mailto:gmcintu...@spraycool.com] Sent: 9 juin 2006 13:27 To: Mike Hurley; David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Mike, I owe you a beer now. You just made my day. Unfortunately since we are unlikely to ever been in the same place I'm taking it upon myself to drink it for you too. I'll let you know if you enjoyed it. Thanks Gary _ From: Mike Hurley [mailto:mikehur...@meadtest.com] Sent: Fri 6/9/2006 9:38 AM To: McInturff Gary; 'David Heald'; 'David Gelfand' Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Gary, Your recollection is correct, Telecom centres were indeed Class B in Europe. It took us several years in the ETSI EE4 committee to get it changed to class A and even then it was by the somewhat devious means of removing emission limits from EN300 386 and instead referencing directly to EN55022. There are probably a few emc-pstc folk who remember the struggle. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff Gary Sent: 09 June 2006 15:50 To: David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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 - 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
RE: EN 301 489-1 emissions question - Euro telecom center A or B classification?
Mike, I owe you a beer now. You just made my day. Unfortunately since we are unlikely to ever been in the same place I'm taking it upon myself to drink it for you too. I'll let you know if you enjoyed it. Thanks Gary _ From: Mike Hurley [mailto:mikehur...@meadtest.com] Sent: Fri 6/9/2006 9:38 AM To: McInturff Gary; 'David Heald'; 'David Gelfand' Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Gary, Your recollection is correct, Telecom centres were indeed Class B in Europe. It took us several years in the ETSI EE4 committee to get it changed to class A and even then it was by the somewhat devious means of removing emission limits from EN300 386 and instead referencing directly to EN55022. There are probably a few emc-pstc folk who remember the struggle. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff Gary Sent: 09 June 2006 15:50 To: David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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 - 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
RE: EN 301 489-1 emissions question - Euro telecom center A or B classification?
Everyone It is also useful to remember that compliance with the relevant harmonised standard(s) allows the manufacturer to place his product on the market, but the potential customer may have additional, more onerous requirements. These would be a contractual matter between the two. So, Class A may be acceptable for placing on the market under the EMC Directive for appropriate locations/environments, but the customer may state a requirement Class B, in his invitation to tender. … and yes, I was also a member of ETSI EE4 a long, long time ago … Best wishes Brian Brian Jones EMC Consultant and Competent Body signatory _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Mike Hurley Sent: 09 June 2006 17:38 To: 'McInturff Gary'; 'David Heald'; 'David Gelfand' Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Gary, Your recollection is correct, Telecom centres were indeed Class B in Europe. It took us several years in the ETSI EE4 committee to get it changed to class A and even then it was by the somewhat devious means of removing emission limits from EN300 386 and instead referencing directly to EN55022. There are probably a few emc-pstc folk who remember the struggle. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff Gary Sent: 09 June 2006 15:50 To: David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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 - 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 - 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
RE: EN 301 489-1 emissions question - Euro telecom center A or B classification?
Gary, Your recollection is correct, Telecom centres were indeed Class B in Europe. It took us several years in the ETSI EE4 committee to get it changed to class A and even then it was by the somewhat devious means of removing emission limits from EN300 386 and instead referencing directly to EN55022. There are probably a few emc-pstc folk who remember the struggle. Mike From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of McInturff Gary Sent: 09 June 2006 15:50 To: David Heald; David Gelfand Cc: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question - Euro telecom center A or B classification? Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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 - 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
Re: EN 301 489-1 emissions question - Euro telecom center A or B classification?
In message 51b0e17d0920404a967d381039139ad0db9...@ds10965.spraycool.com, McInturff Gary gmcintu...@spraycool.com writes I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can?t find the reference. Mustn't interfere with the night guard's TV! (;-) -- John Woodgate - 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
RE: EN 301 489-1 emissions question - Euro telecom center A or B classification?
Same question haunts me – I have a vague recollection that for some odd reason European telecommunications centers were Class B but I can’t find the reference. Maybe the distinction is “telecommunication centers ONLY” So I’m also interested in the answer if some one has it. Thanks Gary _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Heald Sent: Friday, June 09, 2006 7:04 AM To: David Gelfand Cc: emc-p...@ieee.org Subject: Re: EN 301 489-1 emissions question David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. mc-pstc - 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
Re: EN 301 489-1 emissions question
David, I am quite certain that a 'telecommunications center' is a central office. But, before just assuming that Class A is ok for telecom centers, I'd check with the telecom company to be sure that they don't have a requirement for Class B (I have this gut feel that I've run into that but I can't remember any specifics). Best Regards -Dave On 6/9/06, David Gelfand david.gelf...@mitectelecom.com wrote: I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 Douglasmailto:emcp...@ptcnh.net emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: mailto:j.bac...@ieee.org 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 http://www.ieeecommunities.org/emc-pstc - 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
FW: EN 301 489-1 emissions question
To further clarify, it is conducted emissions that is my concern, the unit will likely be under class B radiated limits. From: David Gelfand Sent: 9 juin 2006 09:17 To: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question Let me clarify. The item to be CE marked is an antenna-mast-mounted VSAT rf power amplifier. Regards, David. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Willem Jan Jong Sent: 9 juin 2006 09:07 To: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question David, A and B are vice versa. Class B is for general public. Class A for industrial use. A point-of-sale terminal can be categorized as class B !! Kind regards, Willem Jan Jong From: Willem Jan Jong Sent: vrijdag 9 juni 2006 14:57 To: 'emc-p...@ieee.org' Subject: RE: EN 301 489-1 emissions question David, Class A indeed applies for products meant for the general public. Class B products are meant for industrial users (e.g. telecom providers) operated by occupational workers. A point-of-sale terminal can be categorized as class A. Kind regards, Ir. Willem Jan Jong Product Assessor Certification Telefication B.V. Edisonweg 12 A 6902 PK Zevenaar The Netherlands +31 (0) 316 583 165 From: David Gelfand [mailto:david.gelf...@mitectelecom.com] Sent: vrijdag 9 juni 2006 14:25 To: emc-p...@ieee.org Subject: EN 301 489-1 emissions question I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 - 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 - 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
Re: EN 301 489-1 emissions question
In message a3772c119941df41977965de844184d8ecc...@telefic.telefication.com, Willem Jan Jong wjj...@telefication.com writes Class A indeed applies for products meant for the general public. Class B products are meant for industrial users (e.g. telecom providers) operated by occupational workers. Surely it's the other way round. Class A is 'industrial', excluding 'light industry', which requires Class B, along with 'commercial' and 'residential'. You just might be able to get a Notified Body to agree that no radio or TV receiver is likely to be within 10 m of your product, and thus Class A could be permitted. At some point, these classes will have to be revisited, because many Class A products have found their way into homes, with no obvious adverse consequences. Furthermore, some spectrum management authorities in Europe now regard the LF and MF broadcast bands as 'unprotectable' because of the general level of 'EMC smog', quite a lot being contributed by large numbers of Class B-compliant products. In addition, because the emission limits are based on separations of 3 m, 10 m or 30 m, there is no protection against a receiver being interfered with by a small SMPS only 30 cm away, maybe even its own power supply! -- John Woodgate - 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
RE: EN 301 489-1 emissions question
Although not defined as such, telecommunication centres (Major and Minor) are described in section 5 of ETSI TR 101 651 (free download from www.etsi.org). They generally relate to the ‘public telcoms network’ A ‘point-of-sale terminal system with a rooftop antenna’ would certainly not be a ‘telecommunication centre’ in this context Mike Hurley Director Mead testing ltd Units 23/25 Mead park River Way Harlow CM20 2SE mikehur...@meadtest.com www.meadtest.com phone 44 (0) 1279 635865 fax 44 (0) 1279 635874 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of David Gelfand Sent: 09 June 2006 13:25 To: emc-p...@ieee.org Subject: EN 301 489-1 emissions question I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 - 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
RE: EN 301 489-1 emissions question
Let me clarify. The item to be CE marked is an antenna-mast-mounted VSAT rf power amplifier. Regards, David. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Willem Jan Jong Sent: 9 juin 2006 09:07 To: emc-p...@ieee.org Subject: RE: EN 301 489-1 emissions question David, A and B are vice versa. Class B is for general public. Class A for industrial use. A point-of-sale terminal can be categorized as class B !! Kind regards, Willem Jan Jong From: Willem Jan Jong Sent: vrijdag 9 juni 2006 14:57 To: 'emc-p...@ieee.org' Subject: RE: EN 301 489-1 emissions question David, Class A indeed applies for products meant for the general public. Class B products are meant for industrial users (e.g. telecom providers) operated by occupational workers. A point-of-sale terminal can be categorized as class A. Kind regards, Ir. Willem Jan Jong Product Assessor Certification Telefication B.V. Edisonweg 12 A 6902 PK Zevenaar The Netherlands +31 (0) 316 583 165 From: David Gelfand [mailto:david.gelf...@mitectelecom.com] Sent: vrijdag 9 juni 2006 14:25 To: emc-p...@ieee.org Subject: EN 301 489-1 emissions question I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 - 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 - 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
RE: EN 301 489-1 emissions question
David, A and B are vice versa. Class B is for general public. Class A for industrial use. A point-of-sale terminal can be categorized as class B !! Kind regards, Willem Jan Jong From: Willem Jan Jong Sent: vrijdag 9 juni 2006 14:57 To: 'emc-p...@ieee.org' Subject: RE: EN 301 489-1 emissions question David, Class A indeed applies for products meant for the general public. Class B products are meant for industrial users (e.g. telecom providers) operated by occupational workers. A point-of-sale terminal can be categorized as class A. Kind regards, Ir. Willem Jan Jong Product Assessor Certification Telefication B.V. Edisonweg 12 A 6902 PK Zevenaar The Netherlands +31 (0) 316 583 165 From: David Gelfand [mailto:david.gelf...@mitectelecom.com] Sent: vrijdag 9 juni 2006 14:25 To: emc-p...@ieee.org Subject: EN 301 489-1 emissions question I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 - 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
RE: EN 301 489-1 emissions question
David, Class A indeed applies for products meant for the general public. Class B products are meant for industrial users (e.g. telecom providers) operated by occupational workers. A point-of-sale terminal can be categorized as class A. Kind regards, Ir. Willem Jan Jong Product Assessor Certification Telefication B.V. Edisonweg 12 A 6902 PK Zevenaar The Netherlands +31 (0) 316 583 165 From: David Gelfand [mailto:david.gelf...@mitectelecom.com] Sent: vrijdag 9 juni 2006 14:25 To: emc-p...@ieee.org Subject: EN 301 489-1 emissions question I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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 - 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
EN 301 489-1 emissions question
I need help from our esteemed CE mark experts! EMC radio equipment standard EN 301 489-1 calls out EN 55022 Class B limits in general, and Class A limits for ...equipment intended for use in telecommunication centres only,... What is considered a telecommunication centre? Unfortunately I can not find any definition for this term in the standard, or in any other standards I have consulted. Is a point-of-sale terminal system with a rooftop antenna considered a telecommunication centre? My understanding is that EN 55022 Class B limits apply to residential environments, and Class A applies to commercial and industrial environments. I would hope in our situation that Class A will suffice. If not I am up the proverbial creek without a paddle... Thanks in advance, David. David Gelfand, P.E. Product Integrity Engineer Mitec Telecom Inc 9000 Trans-Canada Highway Montreal QC H9R 5Z8 Canada 514 694 9000 x2262 - 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
Re: Conducted Emissions on Ethernet
In message 041420061600.25253.443FC718000D513562A52206824693CECE020A900A02@comc ast.net, dated Fri, 14 Apr 2006, neve...@comcast.net writes A relatively simple resistive network can be designed for measuring common-mode voltage on Ethernet and many other high-speed interfaces that utilize differential-pair lines, which - with minor modifications - would be perfectly suitable for this application. I have used it for about 10 years, had a paper about it at the Seattle IEEE EMC Symposium (about 8 years ago - coincidently about as long as the standard has been chewed on). Meanwhile it has evolved into a more versatile device than what was described then. But I gues it may be of no interest to people who write standards grin Why don't you tell us more about it, and see? I have problems at present with the revision of EN 55103-1 in respect of conducted emissions: the methods in EN 55022 don't suit every type of port. What interest me most about ports is the conducted emission of a good Late Bottled Vintage into my glass. (;-) -- 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
Re: Conducted Emissions on Ethernet
A relatively simple resistive network can be designed for measuring common-mode voltage on Ethernet and many other high-speed interfaces that utilize differential-pair lines, which - with minor modifications - would be perfectly suitable for this application. I have used it for about 10 years, had a paper about it at the Seattle IEEE EMC Symposium (about 8 years ago - coincidently about as long as the standard has been chewed on). Meanwhile it has evolved into a more versatile device than what was described then. But I gues it may be of no interest to people who write standards grin Neven -- Original message -- From: John Woodgate j...@jmwa.demon.co.uk In message , dated Thu, 13 Apr 2006, jim.hulb...@pb.com writes We have an ethernet port to which is connected a CAT5 cable. When this cable is routed through an ISN per EN 55022 for conducted emissions measurements, the port is unable to function. What experience have people had with ISNs in this application, or what experience do people have with the alternate test methods (current probe and/or voltage probe measurements)? Since it's taken about 8 years to get even a fragile agreement on conducted emissions in CISPR 22/EN 55022, you'd think that everything would be crystal-clear by ! now. I don't know which edition of EN 55022 you are using by the 1998 edition, with corrigenda 1 and 2 and amendments 1 and 2 says in 9.5.3.1: 'Where normal functioning cannot be achieved because of the impact of the ISN on the EUT, the measurement shall be carried out using the method given in 9.5.3.5.' This in turn refers you to Annex C, C.1.3 or C.1.4. C.1.3 uses a current probe and a voltage probe. C.1.4 uses two current probes and a moveable ferrite 'adjuster'. It takes a long time. -- 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-pst! c discu ssion 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 - 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
Re: Conducted Emissions on Ethernet
In message of83d77521.a76d1666-on8525714f.004fc2d9-8525714f.00506...@pb.com, dated Thu, 13 Apr 2006, jim.hulb...@pb.com writes We have an ethernet port to which is connected a CAT5 cable. When this cable is routed through an ISN per EN 55022 for conducted emissions measurements, the port is unable to function. What experience have people had with ISNs in this application, or what experience do people have with the alternate test methods (current probe and/or voltage probe measurements)? Since it's taken about 8 years to get even a fragile agreement on conducted emissions in CISPR 22/EN 55022, you'd think that everything would be crystal-clear by now. I don't know which edition of EN 55022 you are using by the 1998 edition, with corrigenda 1 and 2 and amendments 1 and 2 says in 9.5.3.1: 'Where normal functioning cannot be achieved because of the impact of the ISN on the EUT, the measurement shall be carried out using the method given in 9.5.3.5.' This in turn refers you to Annex C, C.1.3 or C.1.4. C.1.3 uses a current probe and a voltage probe. C.1.4 uses two current probes and a moveable ferrite 'adjuster'. It takes a long time. -- 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
RE: Conducted Emissions on Ethernet
From: jim.hulb...@pb.com [ mailto:jim.hulb...@pb.com] Sent: Thursday, April 13, 2006 7:38 AM To: emc-p...@ieee.org Subject: Conducted Emissions on Ethernet We have an ethernet port to which is connected a CAT5 cable. When this cable is routed through an ISN per EN 55022 for conducted emissions measurements, the port is unable to function. What experience have people had with ISNs in this application, or what experience do people have with the alternate test methods (current probe and/or voltage probe measurements)? We are trying to establish a test procedure that yields repeatable measurements and hopefully measurements that are correlatable to what other labs may measure. Thank you. Jim Hulbert, Principal Engineer GMSE/TSO/Compliance Engineering Pitney Bowes Jim: A few weeks ago, I almost had to face trying to filter an Ethernet cable. My first attempt was to use an Quell EESeal connector insert filter, with a capacitance of 5000 pF from each pin to ground. This produced too much loading (desired signal reduction), and the Ethernet link would not function. So, the only little fact I can add is that 5000 pF (to ground) is too capacitance for the Ethernet interface. Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty - 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
Re: Conducted Emissions on Ethernet
Jim, I am not a test-house, so I don't have experience with various ISNs. However, I have done a considerable amount of work in common-mode voltage and current measurements, as well as investigating imbalance (i.e. mode conversion) in differential-signaling, especially in the hi-speed signaling including Ethernet arena. So maybe I can give a little advice here. I don't know what's wrong with your ISN, but for measuring conducted emission (either CM currents or CM voltages) on high-speed differential signal lines I would never use anything that has RJ45 or similar connectors on it. Just conversion in the connectors and the un-twists of the cable in the area around the connectors can considerably affect common-mode voltages and currents on the signal line, so the measurement results are uncertain. If the un-twists of the twisted pairs at the connector are bad, that can cause considerable crosstalk between the pairs as well. Whatever the test method, the level of balance on the differential pairs must be preserved and not affected, or the results can be anything. For that reason I strongly prefer the clamp method over ISN. Clamp preserves the integrity of the signal line, and ISN is not well-defined in that respect. Some EMC test houses seem not to be aware of that, and I believe that even the ISN manufacturers are not paying attention to it. If I had to use ISN, for whatever reason - maybe for ease and speed of measurement compared with the clamp-test, I'd cut-off the RJ45 receptacles (and maybe some associated segments in the box) from the ISN. I would also cut off the RJ45 plugs from the ends of the cables that connect to it, design a better transition (with better balance, less mode conversion and crosstalk) between the cable that connects the ISN to DUT and from ISN to AUX, and then I'd verify the balance on a 4-port network analyzer. Hard-wiring the ISN into the signal line might do it, keeping extreme care to preserve the balance on the diff pairs. No time or space to elaborate more, but that is essentially keeping the twists of each pair tight and together, and at the same time separating each pair from its neighbor. Regards, Neven -- Original message -- From: jim.hulb...@pb.com We have an ethernet port to which is connected a CAT5 cable. When this cable is routed through an ISN per EN 55022 for conducted emissions measurements, the port is unable to function. What experience have people had with ISNs in this application, or what experience do people have with the alternate test methods (current probe and/or voltage probe measurements)? We are trying to establish a test procedure that yields repeatable measurements and hopefully measurements that are correlatable to what other labs may measure. Thank you. Jim Hulbert, Principal Engineer GMSE/TSO/Compliance Engineering Pitney Bowes- 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 - 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
Conducted Emissions on Ethernet
We have an ethernet port to which is connected a CAT5 cable. When this cable is routed through an ISN per EN 55022 for conducted emissions measurements, the port is unable to function. What experience have people had with ISNs in this application, or what experience do people have with the alternate test methods (current probe and/or voltage probe measurements)? We are trying to establish a test procedure that yields repeatable measurements and hopefully measurements that are correlatable to what other labs may measure. Thank you. Jim Hulbert, Principal Engineer GMSE/TSO/Compliance Engineering Pitney Bowes - 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
RE: Predicting Cable Emissions from Common Mode Current
Doug, Thanks for the link to this fine paper. I like to use NEC simulation to model CM current/radiation. I have found that this works even for CM current excited on large structures such as semiconductor tester boards. Something as seemingly innocent as placing an oscilloscope probe on a signal node can induce enough CM current to couple a signal into other probes on the test board. Dave Cuthbert Micron Technology, Inc. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Doug Smith Sent: Friday, March 03, 2006 12:13 AM To: emc-pstc Subject: Predicting Cable Emissions from Common Mode Current It's that time of the month again and I have posted my latest Technical Tidbit on predicting cable emissions. After an introduction to common mode current measurements, a pdf paper by Mat Aschenberg and Charles Grasso is presented. Abstract: Common mode current measurements are widely used to predict emissions from equipment cables. Mat Aschenberg and Charles Grasso have written an analysis relating common mode current measurements to radiation comparing three different methods. Their treatment is unique in that it addresses the case where the cable is longer than one half wavelength. The results are presented as a pdf file. The link to the article is the picture of the experimental test setup at the bottom of the home page at http://emcesd.com . If any of you want to publish a short paper this way, through my Technical Tidbits, send me an email. I have 14 shows posted at http://emcesd-podcast.com now with several more coming shortly. New shows are posted every week. Doug -- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org - 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 - 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
Re: Uncertainty Calculations for ETS 300 086 Radiated Emissions M easurements
In message 20060215174652.842.qm...@web30506.mail.mud.yahoo.com, dated Wed, 15 Feb 2006, Doug Beckwith dougbeckw...@yahoo.ca writes Isn't CISPR 16-4 the preferred method? This is what was specified to us by our accrediting agency. No. Because the ETSI reference is dated, that is the reference that MUST be used, irrespective of whether there is anything later and/or better. That is why it's necessary to address the fact that there IS no 1998 edition. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - 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
RE: Uncertainty Calculations for ETS 300 086 Radiated Emissions M easurements
Hi, Isn't CISPR 16-4 the preferred method? This is what was specified to us by our accrediting agency. Regards Doug --- Sykes, William Thomas (Tom) wsy...@lucent.com wrote: All: Elliott: If one looks in the back of TR 100028-1 V1.3.1, under Document History, one will find: History Document history Edition 1 March 1992 Publication as ETR 028 Edition 2 March 1994 Publication as ETR 028 V1.3.1 March 2001 Publication, so there was no 1998 version. Of course, there is a version 1.4.1 of -1 and -2 of 12-2001 also. William T. Sykes Lucent Technologies EHS Product Safety/Conformance Manager Room 7B-516A 600-700 Mountain Avenue Murray Hill, NJ 07974-0636 (908)582-6937 -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Elliott Mac-FME001 Sent: Wednesday, February 15, 2006 9:54 AM To: emc-p...@ieee.org Cc: Ho SzeKhian-CSH090 Subject: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements Hello I am in the process of calculating measurement uncertainties for radiated spurious emissions testing per ETS 300 086 V1.2.1, the version that is listed in the OJ as the current version. ETS 300 086 references ETR 028 (1998) for uncertainty calculation. I do not seem to be able to find a copy of ETR 028 (1998) on the ETSI website - older versions are referenced. The latest version I saw was 1994, unless I am missing something in my search. I was able to find a copy of a later version of ETR 028 [v1.3.1 2001-03] that I could use if it is appropriate, even though the current harmonized ETS 300 086 is revision specific... May be best option if I can't get a copy of the 1998 standard. Is anyone out there on RES 02 or have any knowledge of what my best approach would be? Right now I am leaning toward using the 2001 version of ETR 028... Best regards, Mac - 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 - 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 __ Find your next car at http://autos.yahoo.ca - 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
Re: Uncertainty Calculations for ETS 300 086 Radiated Emissions M easurements
In message f5f54e2ec6fec14aac3c9f28e8ee7eb80b8db...@nj9620exch002u.mh.lucent.com, dated Wed, 15 Feb 2006, Sykes, William Thomas (Tom) wsy...@lucent.com writes All: Elliott: If one looks in the back of TR 100028-1 V1.3.1, under Document History, one will find: History Document history Edition 1 March 1992 Publication as ETR 028 Edition 2 March 1994 Publication as ETR 028 V1.3.1 March 2001 Publication, so there was no 1998 version. Of course, there is a version 1.4.1 of -1 and -2 of 12-2001 also. William T. Sykes Lucent Technologies EHS Product Safety/Conformance Manager Room 7B-516A 600-700 Mountain Avenue Murray Hill, NJ 07974-0636 (908)582-6937 -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Elliott Mac-FME001 Sent: Wednesday, February 15, 2006 9:54 AM To: emc-p...@ieee.org Cc: Ho SzeKhian-CSH090 Subject: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements Hello I am in the process of calculating measurement uncertainties for radiated spurious emissions testing per ETS 300 086 V1.2.1, the version that is listed in the OJ as the current version. ETS 300 086 references ETR 028 (1998) for uncertainty calculation. I do not seem to be able to find a copy of ETR 028 (1998) on the ETSI website - older versions are referenced. The latest version I saw was 1994, unless I am missing something in my search. I was able to find a copy of a later version of ETR 028 [v1.3.1 2001-03] that I could use if it is appropriate, even though the current harmonized ETS 300 086 is revision specific... May be best option if I can't get a copy of the 1998 standard. Is anyone out there on RES 02 or have any knowledge of what my best approach would be? Right now I am leaning toward using the 2001 version of ETR 028... Best regards, Mac I hope that someone involved in ETSI reports this matter, so that it can be corrected. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - 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
RE: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements
Thanks - this is just what I needed. I plan on using the latest published revision of the standard [12-2001] even though the 300 086 has the dated reference since there seems to be no 1998 version available. Best regards, Mac _ From: Sykes, William Thomas (Tom) [mailto:wsy...@lucent.com] Sent: Wednesday, February 15, 2006 10:59 AM To: Elliott Mac-FME001; emc-p...@ieee.org Cc: Ho SzeKhian-CSH090 Subject: RE: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements All: Elliott: If one looks in the back of TR 100028-1 V1.3.1, under Document History, one will find: History Document history Edition 1 March 1992 Publication as ETR 028 Edition 2 March 1994 Publication as ETR 028 V1.3.1 March 2001 Publication, so there was no 1998 version. Of course, there is a version 1.4.1 of -1 and -2 of 12-2001 also. William T. Sykes Lucent Technologies EHS Product Safety/Conformance Manager Room 7B-516A 600-700 Mountain Avenue Murray Hill, NJ 07974-0636 (908)582-6937 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Elliott Mac-FME001 Sent: Wednesday, February 15, 2006 9:54 AM To: emc-p...@ieee.org Cc: Ho SzeKhian-CSH090 Subject: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements Hello I am in the process of calculating measurement uncertainties for radiated spurious emissions testing per ETS 300 086 V1.2.1, the version that is listed in the OJ as the current version. ETS 300 086 references ETR 028 (1998) for uncertainty calculation. I do not seem to be able to find a copy of ETR 028 (1998) on the ETSI website - older versions are referenced. The latest version I saw was 1994, unless I am missing something in my search. I was able to find a copy of a later version of ETR 028 [v1.3.1 2001-03] that I could use if it is appropriate, even though the current harmonized ETS 300 086 is revision specific... May be best option if I can't get a copy of the 1998 standard. Is anyone out there on RES 02 or have any knowledge of what my best approach would be? Right now I am leaning toward using the 2001 version of ETR 028... Best regards, Mac - 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 - 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
RE: Uncertainty Calculations for ETS 300 086 Radiated Emissions M easurements
All: Elliott: If one looks in the back of TR 100028-1 V1.3.1, under Document History, one will find: History Document history Edition 1 March 1992 Publication as ETR 028 Edition 2 March 1994 Publication as ETR 028 V1.3.1 March 2001 Publication, so there was no 1998 version. Of course, there is a version 1.4.1 of -1 and -2 of 12-2001 also. William T. Sykes Lucent Technologies EHS Product Safety/Conformance Manager Room 7B-516A 600-700 Mountain Avenue Murray Hill, NJ 07974-0636 (908)582-6937 From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Elliott Mac-FME001 Sent: Wednesday, February 15, 2006 9:54 AM To: emc-p...@ieee.org Cc: Ho SzeKhian-CSH090 Subject: Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements Hello I am in the process of calculating measurement uncertainties for radiated spurious emissions testing per ETS 300 086 V1.2.1, the version that is listed in the OJ as the current version. ETS 300 086 references ETR 028 (1998) for uncertainty calculation. I do not seem to be able to find a copy of ETR 028 (1998) on the ETSI website - older versions are referenced. The latest version I saw was 1994, unless I am missing something in my search. I was able to find a copy of a later version of ETR 028 [v1.3.1 2001-03] that I could use if it is appropriate, even though the current harmonized ETS 300 086 is revision specific... May be best option if I can't get a copy of the 1998 standard. Is anyone out there on RES 02 or have any knowledge of what my best approach would be? Right now I am leaning toward using the 2001 version of ETR 028... Best regards, Mac - 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 - 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
Uncertainty Calculations for ETS 300 086 Radiated Emissions Measurements
Hello I am in the process of calculating measurement uncertainties for radiated spurious emissions testing per ETS 300 086 V1.2.1, the version that is listed in the OJ as the current version. ETS 300 086 references ETR 028 (1998) for uncertainty calculation. I do not seem to be able to find a copy of ETR 028 (1998) on the ETSI website - older versions are referenced. The latest version I saw was 1994, unless I am missing something in my search. I was able to find a copy of a later version of ETR 028 [v1.3.1 2001-03] that I could use if it is appropriate, even though the current harmonized ETS 300 086 is revision specific... May be best option if I can't get a copy of the 1998 standard. Is anyone out there on RES 02 or have any knowledge of what my best approach would be? Right now I am leaning toward using the 2001 version of ETR 028... Best regards, Mac - 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
RE: Humidity and Radiated Emissions Tests
Mac, The biggest effect I've seen was due to the fire retardant in the old cones absorbing moisture and subsequent dielectric changes. We had to put in a humidity controller to keep the chamber and cones at the same RH all the time to get consistant measurements. Bill Barron, Manny manny.bar...@ngc.com wrote: Hello Mac, I don't know the actual physical effect, but there is a requirement in the ANSI C63.4, para 6.1.9. Sincerely, Manny Barron, EMC Engineer Northrop Grumman Mission Systems Intelligence Systems Division Electromagnetic Systems Laboratory 6! 377 San Ignacio Avenue San Jose, California 95119 Phone: 408-531-2430 Email: manny.barron@ mailto:manny.bar...@ngc.com ngc.com Web: www.ngc.com http://www.ngc.com/ _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Elliott Mac-FME001 Sent: Friday, January 13, 2006 11:20 AM To: emc-p...@ieee.org Subject: Humidity and Radiated Emissions Tests Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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 - 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 _ Yahoo! Photos – Showcase holiday pictures in hardcover Photo Books http://us.rd.yahoo.com/mai _us/taglines/photobooks/*http://pa.yaho .com/*http://us.rd.yahoo.com/mail_us/ta lines/photos/evt=38088/*http://pg.photo .yahoo.com/ph//page?.file=photobook_splash.html . You design it and we’ll bind it! - 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
Re: Humidity and Radiated Emissions Tests
In message 20060113213741.90815.qm...@web36805.mail.mud.yahoo.com, dated Fri, 13 Jan 2006, Hans htm...@yahoo.com writes There are formulae for calculating the ERP/EIRP power loss due to moisture content in the air. Typically used when calculating point to point microwave links over several miles and especially over a water body. It seems the loss is near neglible within a 10m distance. It isn't so much power loss in beamed emissions that counts (usually), it's distortions of radiated field patterns. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - 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
Re: Humidity and Radiated Emissions Tests
There are formulae for calculating the ERP/EIRP power loss due to moisture content in the air. Typically used when calculating point to point microwave links over several miles and especially over a water body. It seems the loss is near neglible within a 10m distance. Hans Best Regards Hans Mellberg San Jose, CA 95128, USA __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com - 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
RE: Humidity and Radiated Emissions Tests
You might see effects due to moisture on covers over turntables at OATS facilities. One more argument for 10 meter RF semi-anechoic chambers. :-) Wish we had one. :-( Ghery _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Marko Radojicic Sent: Friday, January 13, 2006 11:42 AM To: Elliott Mac-FME001; emc-p...@ieee.org Subject: RE: Humidity and Radiated Emissions Tests Interesting question! Water is a dielectric with absorptive properties that are frequency dependant. The most well-known peak absorption is the microwave oven 2.4GHz frequency. If you are having EMI issues in this frequency area, you may want to wait for a high-humidity day. 8-) In practice however, I cannot imagine that you would see much variation due to atmospheric RH. Certainly other measurement variation factors would outweigh the water contribution, IMHO. …Marko _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Elliott Mac-FME001 Sent: Friday, January 13, 2006 11:20 AM To: emc-p...@ieee.org Subject: Humidity and Radiated Emissions Tests Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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 - 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 - 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
RE: Humidity and Radiated Emissions Tests
Is the site near the ocean? Salt plays havoc in moist air. Also, if in a dirty environment where particulates are high it could affect readings. These issues however should be able to be accounted for in your uncertainty budget. Dennis Ward Evaluation Engineer American TCB Certification Resource for the Wireless Industry www.atcb.com 703-847-4700 fax 703-847-6888 direct - 703-880-4841 cell - 209-769-8316 NOTICE: This E-Mail message and any attachment may contain privileged or company proprietary information. If you received this message in error, please return to the sender. _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Elliott Mac-FME001 Sent: Friday, January 13, 2006 11:20 AM To: emc-p...@ieee.org Subject: Humidity and Radiated Emissions Tests Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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 - 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
Re: Humidity and Radiated Emissions Tests
In message 54ffbe24c443bc45b8deb804650d2d2ba3a...@ct11exm64.ds.mot.com, dated Fri, 13 Jan 2006, Elliott Mac-FME001 fme...@motorola.com writes What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? The phases of the moons of Neptune can affect radiated emissions tests, or so it seems, sometimes! On an open-air site, there certainly can be effects, especially if surfaces are damp. It's not only condensation, and not only the EUT, that matters. Indoors, I suspect you can find effects if you go looking for them, but usually RH doesn't change very much in the short term. If you measured an EUT at 25% RH and then at 95% RH, the results should only be compared if they were obtained at the same temperature. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - 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
RE: Humidity and Radiated Emissions Tests
Interesting question! Water is a dielectric with absorptive properties that are frequency dependant. The most well-known peak absorption is the microwave oven 2.4GHz frequency. If you are having EMI issues in this frequency area, you may want to wait for a high-humidity day. 8-) In practice however, I cannot imagine that you would see much variation due to atmospheric RH. Certainly other measurement variation factors would outweigh the water contribution, IMHO. …Marko _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Elliott Mac-FME001 Sent: Friday, January 13, 2006 11:20 AM To: emc-p...@ieee.org Subject: Humidity and Radiated Emissions Tests Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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 - 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
RE: Humidity and Radiated Emissions Tests
Hello Mac, I don't know the actual physical effect, but there is a requirement in the ANSI C63.4, para 6.1.9. Sincerely, Manny Barron, EMC Engineer Northrop Grumman Mission Systems Intelligence Systems Division Electromagnetic Systems Laboratory 6377 San Ignacio Avenue San Jose, California 95119 Phone: 408-531-2430 Email: manny.barron@ mailto:manny.bar...@ngc.com ngc.com Web: www.ngc.com http://www.ngc.com/ _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Elliott Mac-FME001 Sent: Friday, January 13, 2006 11:20 AM To: emc-p...@ieee.org Subject: Humidity and Radiated Emissions Tests Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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 - 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
Humidity and Radiated Emissions Tests
Colleagues, What is your opinion - does relative humidity have an effect on radiated emissions testing [as long as there is no condensation on the EUT]? Just curious as to the thoughts out there [or experiences] Best regards, Mac - 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
Re: Suppression of radiated emissions and spread spectrum clocking
This is a multi-part message in MIME format. Isn't it fun, that's why I am not sure if being called an EMC expert is a good thing. Now to the point: 1) Pulling back the Vcc plane away from the edge of the ground plane changes the distribution of the EM field at the edge. While the strength at the edge decreases, it can indeed increase radiation in another direction. There have been papers published on that, e.g. search for Gisin and Tanner in the IEEE EMC Symposia or Transactions records. However, what is the practical application and usefulness? While the radiation pattern is changed, one should notice that on the typical PCBs none of the mechanisms of radiations (edge-fringing or Patch-antenna) are not efficient radiators, and in my experience the direct radiation off the PCB edge or off the (undercut) Vcc plane is typically not a problem, because Vcc planes are typically at an electrically very small distance to the ground planes (even in a not-so-good PCB stackup), and the field falls-off quickly with the distance from the edge of the Vcc plane (wherever it is! ). Also, in many cases, the Vcc planes are in between other plane (ground) layers, which again changes the field distribution and coupling and radiation mechanisms (there is no patch-antenna in the PCB if it is sandwitched in the inner layers). The typical practical problem with the edge-radiation that I have seen is not the direct radiation, rather it is when the PCB-edge is close to a piece of metal that is electrically larger, e.g. card-cage in a chassis. The field at the edge in that case feeds the larger antenna (piece of metal), which then radiates as a secondary-radiator much more efficiently. Another similar situation is in the areas of the PCB-moats. The Vcc that is extended all the way to the ground plane edge (of the moat) can very efficiently couple the EM field into the moat, which then easily guides it and couples to the I/O across the moat, e.g. a transformer. In such a case, the transformer and/or common-mode choke across the moat do not suppress the common-mode energy coupled to them. The papers I have seen only concentrate on the redirection of energy, but fail to recognize that the real practical issue is typycally not the direct radiation but the secondary radiation. I'd say, the expert who is stating that it is uselles is definitelly wrong - sometimes it is very benefitial as described above (and witnessed in extensive practice). It is also true that sometimes it does not matter. The expert who said it CAN definitely help is right - it depends on the circumstances. It is typically easy to pull the Vcc planes back and stitch the “ground” planes together at the edges, which eliminates the issue with emission coming from secondary radiators - so why not do it? However, the energy is still going somewhere inside the PCB stackup, so the signal routing, PCB-stackup, bypassing etc. can/should/must be used to minimize the levels and the coupling with the PCB structures that can radiate or carry it to the I/O sections. 2) Spread-spectrum is frequency modulation of the clock signal. If one looks in any textbook on the topic (or remembers from the school), in FM the side-bands receive power from the carrier, so that the deeper the modulation is the power (hence the amplitude) of the carrier is lower and the power (the amplitude) of the side-bands is higher – the total power in the signal is constant. The ideal SS technique, from the point of view of minimizing the radiated emission maximum amplitude) is such that the level at the carrier frequency and the level at the sidebands are equal. Any deeper modulation and the sidebands are higher than in the equilibrium, and any lower modulation and the carrier is higher (thus they are not optimal). Also, the waveform of the modulating signal can make large difference, check Lexmark web page on that. I'd say the expert was wrong on the second one. Again - see the math of how FM works. Cheers, Neven Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? Second question. A well-known EMI speaker/author also states that spread spectrum clocking (SSC) does not lower peak radiated emissions. Rather the harmonics of SSC are spread out where the Quasi Peak Detector Spectrum Analyzer (QPDSA) is missing (incorrect frequency band) their peak value readings, i.e. fpeak is outside the frequency band that SPDSA is set for monitoring. Thanks. Robert Hanson - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http
Re: Suppression of radiated emissions and spread spectrum clocking
Cortland, The Ansoft URL's pdf comes up nil. Going to the \thewave\ index doesn't list that .pdf Would you send me a copy? - Robert - On Sun, 27 Nov 2005 20:47:48 -0500 Cortland Richmond 72146@compuserve.com wrote: Ken Javor wrote I didn't know what the 20 H rule was either, just assumed everyone else did... See http://www.qsl.net/wb6tpu/si-list4/0391.html page 9 of http://www.ansoft.com/thewave/Shielding_and_Decoupling.pdf http://factaee.elfak.ni.ac.yu/fu2k12/fu04.html and others (search on 20H rule.) RF between two equally sized planes does radiate from the slot formed at the edge - but RF on a small plane over a larger one also radiates from the slot around the smaller. We don't want to put patch antennas on a board while trying to avoid other problems. Thus the controversy. Cortland KA5S - 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/listserv/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
Re: Suppression of radiated emissions and spread spectrum clocking
Thank you, now that I understand that 20 H means the power plane outside edge is set back from the ground plane edge a distance 20 times the separation between the two planes, it is possible to opine on the subject. Looking at the fringing field set up by potentials and gradients between the two planes, if you follow the 20 H rule the radiation efficiency will be much less, the quasi-static and induction fields will be there, but much less of the energy will break off and radiated as a traveling electromagnetic wave. From: Cortland Richmond 72146@compuserve.com Date: Sun, 27 Nov 2005 20:47:48 -0500 To: ieee pstc list emc-p...@ieee.org Subject: Re: Suppression of radiated emissions and spread spectrum clocking Ken Javor wrote I didn't know what the 20 H rule was either, just assumed everyone else did... See http://www.qsl.net/wb6tpu/si-list4/0391.html page 9 of http://www.ansoft.com/thewave/Shielding_and_Decoupling.pdf http://factaee.elfak.ni.ac.yu/fu2k12/fu04.html and others (search on 20H rule.) RF between two equally sized planes does radiate from the slot formed at the edge - but RF on a small plane over a larger one also radiates from the slot around the smaller. We don't want to put patch antennas on a board while trying to avoid other problems. Thus the controversy. Cortland KA5S - 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/listserv/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 - 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/listserv/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
Re: Suppression of radiated emissions and spread spectrum clocking
Ken Javor wrote I didn't know what the 20 H rule was either, just assumed everyone else did... See http://www.qsl.net/wb6tpu/si-list4/0391.html page 9 of http://www.ansoft.com/thewave/Shielding_and_Decoupling.pdf http://factaee.elfak.ni.ac.yu/fu2k12/fu04.html and others (search on 20H rule.) RF between two equally sized planes does radiate from the slot formed at the edge - but RF on a small plane over a larger one also radiates from the slot around the smaller. We don't want to put patch antennas on a board while trying to avoid other problems. Thus the controversy. Cortland KA5S - 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/listserv/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
Re: Suppression of radiated emissions and spread spectrum clocking
I didn't know what the 20 H rule was either, just assumed everyone else did... From: John Woodgate j...@jmwa.demon.co.uk Date: Sun, 27 Nov 2005 18:49:13 + To: emc-p...@ieee.org Subject: Re: Suppression of radiated emissions and spread spectrum clocking americo...@aol.com wrote (in 26c.a77014.30bb4...@aol.com) about 'Suppression of radiated emissions and spread spectrum clocking', on Sun, 27 Nov 2005: Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? What is 'the 20 H rule'? -- Regards, John Woodgate, OOO - Own Opinions Only. Deadlines are 90% of deadliness. http://www.jmwa.demon.co.uk Also see http://www.isce.org.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/listserv/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 - 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/listserv/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
Re: Suppression of radiated emissions and spread spectrum clocking
americo...@aol.com wrote (in 26c.a77014.30bb4...@aol.com) about 'Suppression of radiated emissions and spread spectrum clocking', on Sun, 27 Nov 2005: Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? What is 'the 20 H rule'? -- Regards, John Woodgate, OOO - Own Opinions Only. Deadlines are 90% of deadliness. http://www.jmwa.demon.co.uk Also see http://www.isce.org.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/listserv/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
Re: Suppression of radiated emissions and spread spectrum clocking
Reply to second question only. In a limited sense it is correct that a spread spectrum clock doesn't decrease emissions, it spreads them out (in the frequency domain). The spread spectrum clock decreases the amount of time a signal is within the pass-band of the receiver, making it appear a broadband signal which is properly attenuated or filtered by a quasi-peak detector. As long as the resolution bandwidth (120 kHz) is a proper simulation of the spectrum allocation for a radio broadcast protected by the RE limit, all is well. If however the protected broadcast has much wider spectral content than the measurement bandwidth, such as occurs with a television broadcast (4 MHz), then the dithering results in shifting the spectrum around within the pass band of the victim receiver and it is still a narrowband signal captured continuously by the victim. In that case the quasi-peak detector does not properly address the nuisance value of the interference. No direct experience with the following, but it makes sense intuitively. Have heard anecdotes that clock dithering can actually increase TVI over a cw interference signal. Essentially clock dithering that does not push spectral content out of the pass-band introduces frequency modulation in-band, and it is often the case that a modulated signal causes more interference than a purely cw tone. From: americo...@aol.com List-Post: emc-pstc@listserv.ieee.org Date: Sun, 27 Nov 2005 12:37:23 EST To: emc-p...@ieee.org Subject: Suppression of radiated emissions and spread spectrum clocking Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? Second question. A well-known EMI speaker/author also states that spread spectrum clocking (SSC) does not lower peak radiated emissions. Rather the harmonics of SSC are spread out where the Quasi Peak Detector Spectrum Analyzer (QPDSA) is missing (incorrect frequency band) their peak value readings, i.e. fpeak is outside the frequency band that SPDSA is set for monitoring. Thanks. Robert Hanson - 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/listserv/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 From: americo...@aol.com List-Post: emc-pstc@listserv.ieee.org Date: Sun, 27 Nov 2005 12:35:46 EST To: emc-p...@ptcnh.net Cc: americomsemin...@aol.com Subject: Suppression of radiated emissions and spread spectrum clocking Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? Second question. A well-known EMI speaker/author also states that spread spectrum clocking (SSC) does not lower peak radiated emissions. Rather the harmonics of SSC are spread out where the Quasi Peak Detector Spectrum Analyzer (QPDSA) is missing (incorrect frequency band) their peak value readings, i.e. fpeak is outside the frequency band that SPDSA is set for monitoring. Thanks. Robert Hanson - 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/listserv/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 - This message
Suppression of radiated emissions and spread spectrum clocking
This is a multi-part message in MIME format. Conformity and SI List I attended an electronic conference where a well-known EMI/EMC speaker/author stated that the 20 H rule is useless for suppression of radiated emissions. On the other hand, another well known EMI/EMC speaker/author states that it can definitely help. What is the opinion of conformity (SI) members and what empirical results have been obtained? Second question. A well-known EMI speaker/author also states that spread spectrum clocking (SSC) does not lower peak radiated emissions. Rather the harmonics of SSC are spread out where the Quasi Peak Detector Spectrum Analyzer (QPDSA) is missing (incorrect frequency band) their peak value readings, i.e. fpeak is outside the frequency band that SPDSA is set for monitoring. Thanks. Robert Hanson - 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/listserv/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 ---BeginMessage--- This attachment, originally named Message Text, was removed because it is zero length. ---End Message---
Japanese emissions requirements near 5 GHz
Hello Mario, Thank you for your reply. Perhaps I asked the wrong question. We have an intentional radiator with a 10th harmonic of the oscillator that is less than 300 MHz, but the switch mode supply generates impulses measured in the 5 GHz region. We have been told that the product is noisy by a consultant of the government. What I am trying to determine is if any 5 GHz regulation or standard has been violated. As the noise source is switching noise, I do not believe that an intentional radiator spec in the 5 GHz band would apply. Do you have any thoughts on this? What regulations or standards does Japan have in place for incidental emissions near 5 GHz? Regards, Don Umbdenstock Manager Compliance Engineering Tyco Safety Products / Sensormatic 6600 Congress Avenue Boca Raton, FL 33487 USA 561.912.6440 djumbdenst...@tycoint.com _ From: mlehm...@herberg-sp.de [mailto:mlehm...@herberg-sp.de] Sent: Tuesday, October 11, 2005 7:45 AM To: djumbdenst...@tycoint.com Cc: emc-p...@ieee.org Subject: Antwort: VCCI testing above 1 GHz Dear Don, as long as the technical requirements in V3-2005.04 are valid, you just need to perform measurements up to 1 GHz. In the actual Japanese standard it is referred to CISPR 22:1997. Kind regards i.V. Mario Lehmann Geschäftsbereich European Compliance Laboratory HERBERG. Service Plus GmbH Tel:+49 911 59835-923 Nordostpark 51 Fax:+49 911 59835-90 90411 Nürnberg mailto: mailto:mlehm...@herberg-sp.de mlehm...@herberg-sp.de http://www.herberg-sp.de/ http://www.herberg-sp.de djumbdenst...@tycoint.com Gesendet von: emc-p...@ieee.org 05.10.2005 18:25 An emc-p...@ieee.org Kopie Thema VCCI testing above 1 GHz With the change in CISPR 22, anyone know how testing above 1 GHz is being addressed in Japan today? Don Umbdenstock Manager Compliance Engineering Tyco Safety Products / Sensormatic 6600 Congress Avenue Boca Raton, FL 33487 USA 561.912.6440 djumbdenst...@tycoint.com From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Monday, October 03, 2005 10:49 AM To: Gordon,Ian Cc: emc-p...@ieee.org Subject: RE: Above 1 GHz EMI testing with horn antenna Rumor (I stress, rumor) has it that we should see both EN 55022:2005 and Amendment A1:2005 to EN 55022:2005 show up in the OJ in November. We'll see what the date of withdrawal is then. Ghery From: Gordon,Ian [mailto:ian.gor...@bocedwards.com] Sent: Monday, October 03, 2005 1:40 AM To: Pettit, Ghery Cc: emc-p...@ieee.org Subject: RE: Above 1 GHz EMI testing with horn antenna Ghery Do you know if there a timetable for publishing this in the European OJ as an ammendment to EN55022? Ian Gordon -Original Message- From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: 02 October 2005 04:12 To: bdew...@ix.netcom.com; Dward ATCB; regula...@relia.net; emcp...@aol.com Cc: emc-p...@ieee.org Subject: RE: Above 1 GHz EMI testing with horn antenna Well, it isn't a proposed CISPR 22 standard anymore. Amendment 1 to CISPR 22:2005 was published in July and provides limits from 1 GHz to 6 GHz. The actual test methods, etc are provided in the CISPR 16 series of documents. See the amendment for the specific citations. No height scan is required for CISPR 22 above 1 GHz IFF (remember the old algebra IFF - If and only if?) the EUT falls within the beam width of the antenna. Otherwise, some height scanning is needed. Again, look at the amendment and read the cited portions from CISPR 16-x. No bore sighting either way. Ghery S. Pettit Intel Corporation *** The information contained in this email and any attachments may be confidential and is provided solely for the use of the intended recipient(s). If you are not the intended recipient, you are hereby notified that any disclosure, distribution, or use of this e-mail, its attachments or any information contained therein is unauthorised and prohibited. If you have received this in error, please contact the sender immediately and delete this e-mail and any attachments. No responsibility is accepted for any virus or defect that might arise from opening this e-mail or attachments, whether or not it has been checked by anti-virus software. - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp
Re: Measuring Conducted Emissions above 30 Mhz
A note about MIL-STD-461. Obsolete versions (basic release through -461C) controlled conducted emissions to 50 MHz. But they did this by limiting the power cord length to a maximum of one meter from test sample to 10 uF feedthrough capacitor, the latter used instead of an inductive LISN. At 50 MHz, the power cord would be one-sixth wavelength, and there were instructions in MIL-STD-462 to physically scan the current probe looking for a current maximum. For radiated tests, the power cord length was increased to two meters. Unfortunately a lot of lazy people used one length or the other for all tests, to the point that when MIL-STD-461D/-462D came along, they scrapped the two different power cord lengths for a single length of 2.5 meters. The upper frequency limit was lowered to 10 MHz because of the longer leads. There is wording in the appendix to the effect that if control is desired to higher frequencies, the power cord length needs to be shortened. RTCA/DO-160 controls conducted emissions over exactly the same frequency range as CISPR, namely 150 kHz to 30 MHz, although they used to mandate a 5 uH LISN and nowadays it seems like you could use any LISN impedance from 5 to 50 uH. Is that a correct interpretation? It doesn't seem right, but that's how I interpreted the latest curves. From: Kurt Fischer kurt.fisc...@hyperinterop.com Reply-To: kurt.fisc...@hyperinterop.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 29 Sep 2005 16:03:49 -0700 To: emc-p...@ieee.org Subject: RE: Measuring Conducted Emissions above 30 Mhz Hi all, A few standards come to mind depending on product application: MIL - STD 461/462 has conducted power line emissions measurements to higher frequencies (do not remember how high?). Also RTCA DO-160 for aircraft products / environments. Also consider CISPR 14 (absorption clamp method) for Household Products (or motors). This test method covers at least 300 MHz. Good Luck. Kurt Fischer From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Ken Javor Sent: Thursday, September 29, 2005 10:21 AM To: emc-p...@ieee.org Subject: Re: Measuring Conducted Emissions above 30 Mhz If you are going to make repeatable measurements two things have to hold true. The LISN has to continue to provide its function, and the LISN has to be close enough to the EUT that the mismatch between EUT, power cord and LISN doesn't cause vswr errors. At 30 MHz, the power cord should be l/10, or one meter. Of course that isn't the case, so there is already some question as to the accuracy of the present measurement stopping at 30 MHz. It is pretty easy to design a 50 uH LISN to 100 MHz, but you should check. Also, there are 5 uH LISNs that have been designed to 400 MHz. Above about 2 MHz, it doesn't matter whether you use a 5 or 50 uH LISN, so you have that possible alternative. If it were me, and I wanted to make accurate and repeatable CE measurements, I would either shorten the power cord to one-tenth wavelength, or I would go to a current probe measurement and slide the current probe up and down the power cord looking for peaks (spectrum analyzer in max hold while scanning frequencies and scanning the probe). I also think it would be very important to discriminate between different conduction modes, dm or cm or super-cm (current flowing same sense in phase, neutral and safety ground). From: Garnier, David S (GE Healthcare) david.garn...@med.ge.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 29 Sep 2005 10:55:58 -0500 To: emc-p...@ieee.org Subject: Measuring Conducted Emissions above 30 Mhz Hello EMC Guru's, I am looking for some guidance... Is there an established Standard Test Method for measuring AC Power Conducted Emissions above 30 MHz (say to 150 MHz?) ((Obviously, CE limits for CISPR11 only go to 30 Mhz.)) Thanks for your time, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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
RE: Measuring Conducted Emissions above 30 Mhz
Hi all, A few standards come to mind depending on product application: MIL - STD 461/462 has conducted power line emissions measurements to higher frequencies (do not remember how high?). Also RTCA DO-160 for aircraft products / environments. Also consider CISPR 14 (absorption clamp method) for Household Products (or motors). This test method covers at least 300 MHz. Good Luck. Kurt Fischer From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Ken Javor Sent: Thursday, September 29, 2005 10:21 AM To: emc-p...@ieee.org Subject: Re: Measuring Conducted Emissions above 30 Mhz If you are going to make repeatable measurements two things have to hold true. The LISN has to continue to provide its function, and the LISN has to be close enough to the EUT that the mismatch between EUT, power cord and LISN doesn't cause vswr errors. At 30 MHz, the power cord should be l/10, or one meter. Of course that isn't the case, so there is already some question as to the accuracy of the present measurement stopping at 30 MHz. It is pretty easy to design a 50 uH LISN to 100 MHz, but you should check. Also, there are 5 uH LISNs that have been designed to 400 MHz. Above about 2 MHz, it doesn't matter whether you use a 5 or 50 uH LISN, so you have that possible alternative. If it were me, and I wanted to make accurate and repeatable CE measurements, I would either shorten the power cord to one-tenth wavelength, or I would go to a current probe measurement and slide the current probe up and down the power cord looking for peaks (spectrum analyzer in max hold while scanning frequencies and scanning the probe). I also think it would be very important to discriminate between different conduction modes, dm or cm or super-cm (current flowing same sense in phase, neutral and safety ground). From: Garnier, David S (GE Healthcare) david.garn...@med.ge.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 29 Sep 2005 10:55:58 -0500 To: emc-p...@ieee.org Subject: Measuring Conducted Emissions above 30 Mhz Hello EMC Guru's, I am looking for some guidance... Is there an established Standard Test Method for measuring AC Power Conducted Emissions above 30 MHz (say to 150 MHz?) ((Obviously, CE limits for CISPR11 only go to 30 Mhz.)) Thanks for your time, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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
Re: Measuring Conducted Emissions above 30 Mhz
If you are going to make repeatable measurements two things have to hold true. The LISN has to continue to provide its function, and the LISN has to be close enough to the EUT that the mismatch between EUT, power cord and LISN doesn't cause vswr errors. At 30 MHz, the power cord should be l/10, or one meter. Of course that isn't the case, so there is already some question as to the accuracy of the present measurement stopping at 30 MHz. It is pretty easy to design a 50 uH LISN to 100 MHz, but you should check. Also, there are 5 uH LISNs that have been designed to 400 MHz. Above about 2 MHz, it doesn't matter whether you use a 5 or 50 uH LISN, so you have that possible alternative. If it were me, and I wanted to make accurate and repeatable CE measurements, I would either shorten the power cord to one-tenth wavelength, or I would go to a current probe measurement and slide the current probe up and down the power cord looking for peaks (spectrum analyzer in max hold while scanning frequencies and scanning the probe). I also think it would be very important to discriminate between different conduction modes, dm or cm or super-cm (current flowing same sense in phase, neutral and safety ground). From: Garnier, David S (GE Healthcare) david.garn...@med.ge.com List-Post: emc-pstc@listserv.ieee.org Date: Thu, 29 Sep 2005 10:55:58 -0500 To: emc-p...@ieee.org Subject: Measuring Conducted Emissions above 30 Mhz Hello EMC Guru's, I am looking for some guidance... Is there an established Standard Test Method for measuring AC Power Conducted Emissions above 30 MHz (say to 150 MHz?) ((Obviously, CE limits for CISPR11 only go to 30 Mhz.)) Thanks for your time, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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
Measuring Conducted Emissions above 30 Mhz
Hello EMC Guru's, I am looking for some guidance... Is there an established Standard Test Method for measuring AC Power Conducted Emissions above 30 MHz (say to 150 MHz?) ((Obviously, CE limits for CISPR11 only go to 30 Mhz.)) Thanks for your time, Dave Garnier David Garnier e GE Health Care ___ David S. Garnier Senior Technician Functional CT Engineering 3000 N. Grandview Ave - M/S W-1250 Waukesha, Wi. 53188 Tel: 262.312.7246 Cel: 414.899.7580 - 2005 IEEE Symposium on Product Safety Engineering 3-4 October Schaumburg, IL http://www.ieee-pses.org/symposium 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/listserv/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
EMC test laboratory with lead shielded enclosure for emissions testing
Hello, Does anyone know of a laboratory for hire (preferably in the Northeast US) that has a 10 meter radiated emissions test site that is also lead shielded for testing X-ray equipment? The test site would also need 400 or 480 VAC and greater than 100 ampere power supply capability. Thanks, Michael Peters The information transmitted in this message is confidential and may be privileged. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify Analogic Corporation immediately - by replying to this message or by sending an email to deliveryerr...@analogic.com - and destroy all copies of this information, including any attachments, without reading or disclosing them. Thank you. 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Use of Dipole Antenna's For FCC-A Emissions Testing
I may be thinking of CISPR 16, but I know there is a standard that says a tuned dipole, if used vertical, must remain tuned to 80 MHz or so for measurements down to 30 MHz. To properly do this, however, requires calibration factors acquired in that mode as well. Bob Richards, NCT. Pettit, Ghery ghery.pet...@intel.com wrote: Jeff, ANSI C63.4 still lists the tuned dipole antenna as the preferred antenna for measurements from 30 MHz to 1000 MHz. Vertically polarized you must keep the antenna at least .25 meters above the ground plane, so, yes, you cannot get the center of the antenna 1 meter off the ground plane. Perfectly legal. Just as it was when we did this (not very often, as I recall) at Tandem in the “good old days”. Ghery S. Pettit _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of jeff collins Sent: Friday, August 26, 2005 5:47 PM To: emc-p...@ieee.org Subject: Use of Dipole Antenna's For FCC-A Emissions Testing Hi Group, It's been quite a while since I've done this so I figure I would ping it off the group for a consensus. Back in the old days, you could use a Dipole antenna to take radiated emission measurements for frequencies that were either failing or were close to the limit. Is that still legal for FCC-A radiated emissions testing? For background info, by tuning the dipole antenna to the exact frequency, you were able to obtain a more accurate reading than using a broadband antenna. Sometimes you would gain a few dB, sometimes you would lose a few dB. One thing I remember about this that was flakey, was if you did this for a low end frequency such as 30 Mhz in vertical polarity. At that frequency, the elements on the dipole antenna seem to be about a mile long. There was no way to take a vertical reading at that frequency at a height of 1 meter without breaking the antenna element. You therefore had to raise the antenna above 2+ meters to take the reading. In horizontal polarity this was not an issue. All comments appreciated. Thanks, Jeff Collins 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Use of Dipole Antenna's For FCC-A Emissions Testing
That is CISPR. ANSI C63.4 does not call for setting the antenna to an 80 MHz resonant length below 80 MHz. That would result in a difference in readings between the two approaches. Ghery _ From: Bob Richards [mailto:b...@toprudder.com] Sent: Monday, August 29, 2005 7:10 AM To: Pettit, Ghery; emc-p...@ieee.org Subject: RE: Use of Dipole Antenna's For FCC-A Emissions Testing I may be thinking of CISPR 16, but I know there is a standard that says a tuned dipole, if used vertical, must remain tuned to 80 MHz or so for measurements down to 30 MHz. To properly do this, however, requires calibration factors acquired in that mode as well. Bob Richards, NCT. Pettit, Ghery ghery.pet...@intel.com wrote: Jeff, ANSI C63.4 still lists the tuned dipole antenna as the preferred antenna for measurements from 30 MHz to 1000 MHz. Vertically polarized you must keep the antenna at least .25 meters above the ground plane, so, yes, you cannot get the center of the antenna 1 meter off the ground plane. Perfectly legal. Just as it was when we did this (not very often, as I recall) at Tandem in the “good old days”. Ghery S. Pettit _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of jeff collins Sent: Friday, August 26, 2005 5:47 PM To: emc-p...@ieee.org Subject: Use of Dipole Antenna's For FCC-A Emissions Testing Hi Group, It's been quite a while since I've done this so I figure I would ping it off the group for a consensus. Back in the old days, you could use a Dipole antenna to take radiated emission measurements for frequencies that were either failing or were close to the limit. Is that still legal for FCC-A radiated emissions testing? For background info, by tuning the dipole antenna to the exact frequency, you were able to obtain a more accurate reading than using a broadband antenna. Sometimes you would gain a few dB, sometimes you would lose a few dB. One thing I remember about this that was flakey, was if you did this for a low end frequency such as 30 Mhz in vertical polarity. At that frequency, the elements on the dipole antenna seem to be about a mile long. There was no way to take a vertical reading at that frequency at a height of 1 meter without breaking the antenna element. You therefore had to raise the antenna above 2+ meters to take the reading. In horizontal polarity this was not an issue. All comments appreciated. Thanks, Jeff Collins 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Use of Dipole Antenna's For FCC-A Emissions Testing
Jeff, ANSI C63.4 still lists the tuned dipole antenna as the preferred antenna for measurements from 30 MHz to 1000 MHz. Vertically polarized you must keep the antenna at least .25 meters above the ground plane, so, yes, you cannot get the center of the antenna 1 meter off the ground plane. Perfectly legal. Just as it was when we did this (not very often, as I recall) at Tandem in the “good old days”. Ghery S. Pettit _ From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of jeff collins Sent: Friday, August 26, 2005 5:47 PM To: emc-p...@ieee.org Subject: Use of Dipole Antenna's For FCC-A Emissions Testing Hi Group, It's been quite a while since I've done this so I figure I would ping it off the group for a consensus. Back in the old days, you could use a Dipole antenna to take radiated emission measurements for frequencies that were either failing or were close to the limit. Is that still legal for FCC-A radiated emissions testing? For background info, by tuning the dipole antenna to the exact frequency, you were able to obtain a more accurate reading than using a broadband antenna. Sometimes you would gain a few dB, sometimes you would lose a few dB. One thing I remember about this that was flakey, was if you did this for a low end frequency such as 30 Mhz in vertical polarity. At that frequency, the elements on the dipole antenna seem to be about a mile long. There was no way to take a vertical reading at that frequency at a height of 1 meter without breaking the antenna element. You therefore had to raise the antenna above 2+ meters to take the reading. In horizontal polarity this was not an issue. All comments appreciated. Thanks, Jeff Collins 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Use of Dipole Antenna's For FCC-A Emissions Testing
Hi Group, It's been quite a while since I've done this so I figure I would ping it off the group for a consensus. Back in the old days, you could use a Dipole antenna to take radiated emission measurements for frequencies that were either failing or were close to the limit. Is that still legal for FCC-A radiated emissions testing? For background info, by tuning the dipole antenna to the exact frequency, you were able to obtain a more accurate reading than using a broadband antenna. Sometimes you would gain a few dB, sometimes you would lose a few dB. One thing I remember about this that was flakey, was if you did this for a low end frequency such as 30 Mhz in vertical polarity. At that frequency, the elements on the dipole antenna seem to be about a mile long. There was no way to take a vertical reading at that frequency at a height of 1 meter without breaking the antenna element. You therefore had to raise the antenna above 2+ meters to take the reading. In horizontal polarity this was not an issue. All comments appreciated. Thanks, Jeff Collins 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
CISPR 22 and emissions above 1GHz
for those interested. The URL is long and you may need to unwrap it to use it. http://www.iec.ch/online_news/etech/arch_2005/etech_0805/new s.htm?mlref=e-tech#emc_limits Regards, Peter L. Tarver, PE ptar...@ieee.org 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/listserv/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 Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
ethernet radiated emissions- thanks
Dear colleagues; I would like to thank all those who replied to my predicament regarding emissions from an Ethernet port. I have had some first-class advice which will help me solve the problem. Many thanks; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com ***LEGAL DISCLAIMER: READ THIS FIRST*** This Email and any files transmitted with it are confidential and intended solely for the use of the individual to whom or the entity to which they are addressed. If you have received this email in error please notify the sender immediately. Please note that any views or opinions presented in this email are those of the author and do not necessarily represent those of Allen Heath Limited. This email has been checked for the presence of viruses using Sophos AV Scanner. Anti-virus updates are downloaded on a daily basis . The recipient should also check this email and any attachments for the presence of viruses. Allen Heath Limited accepts no liability for any damage caused by any virus transmitted via this email. *** 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ethernet radiated emissions
Ian, A signal that strong suggests one possibility to me. It is possible that the board layout was automatically routed. As a result a clock trace was run through the Ethernet magnetics area. This area should be clear of everything but the Ethernet signals. The application notes for the Ethernet interface chipset or magnetics may be of help. If you do find a clock trace routed in this area, try cutting the trace, at both ends, and running a wire on the board and kept away from all I/O ports. You may need to terminate your re-routed clock line. Of course this is only one possibility, but one I have encountered that caused a similar failure. Good luck. Eric Lifsey At 12:17 PM +0100 6/17/05, McBurney, Ian [Allen Heath UK] wrote: Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ethernet radiated emissions
Ian, the question you posted is so generic that nobody can really answer it. It does not give any clue regarding the sources and mechanisms of emission, no results of your troubleshooting, nor does it give any insight into the product and possible causes of the increased emission. If you provide much more details, someone on the reflector might try to help you. Posting the results of your homework would help others help you, and would show that you have done it before asking for help. If you can't, then I believe you might be better off hiring an expert to help you with the problem. STP did not give you much reduction for some or all of the following reasons: 1) The shield is crimped to the shell of the Ethernet plug with only one wire (that's standard), and then the shell makes contact with the shell of the receptacle only with two tabs on its sides. This is far from a good RF 360 deg contact required for good performance of a shield. 2) The location where the shell/shield makes contact with the product is at a considerable RF (ground-noise, i.e. common-mode) potential, so it is driving the shield 3) The shield of the UTP is not really good to start with Regards, Neven -- Original message -- Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ethernet radiated emissions
Ian, The problem is probably a common-mode signal from some other source using the Ethernet cable as an antenna, as Ken Javor has suggested. The 20dB failure is strong evidence of that because an Ethernet signal based failure would not be that strong. Besides, 33 MHz is not a clock frequency used by 100Base-T, I don’t believe. Attacking the common-mode source on the PCB is the most effective thing to do, as others have suggested. But sometimes this is difficult. As far as STP is concerned, it will do you no good if the board-side connector (jack) is not shielded. Some are not. If the board-side receptacle is shielded, many are configured so that the jack’s shield does not make good contact to the enclosure panel. If it doesn’t, then the effectiveness of the shielding is problematic. If you don’t have a conductive enclosure to connect to, then STP may not help you much with common-mode radiation anyway. Twisted pair Ethernet can be a challenge, but the coaxial version, 10Base-2 was worse. Jim _ James L. Knighten, Ph.D. Teradata, a division of NCR http://www.ncr.com 17095 Via del Campo San Diego, CA 92127 tel: 858-485-2537 fax: 858-485-3788 _ From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Ken Javor Sent: Friday, June 17, 2005 5:30 AM To: McBurney, Ian [Allen Heath UK]; emc-p...@ieee.org Subject: Re: ethernet radiated emissions No experience with Ethernet per se, so this is a very general comment. It sounds as if the emissions are common mode. If so, they may not have anything to do with the Ethernet itself, the Ethernet may be a fortuitous conductor. I would check this using a current probe around the cable, with and without Ethernet traffic. If there is little or no difference, it is ground bounce in the printed circuit board driving conducted emissions onto the Ethernet. Then you have to look at suppressing emissions from that source. From: McBurney, Ian [Allen Heath UK] ian.mcbur...@allen-heath.com List-Post: emc-pstc@listserv.ieee.org Date: Fri, 17 Jun 2005 12:17:17 +0100 To: emc-p...@ieee.org Subject: ethernet radiated emissions Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ethernet radiated emissions
33MHz - sounds like PCI bus. The radiation originating from Ethernet is very broadband per se as the data is scrambled using a pseudo-random code, thus widening the spectrum. This was intended to reduce EMI. There are several things to think of: - The traces between the magnetics and the connector must be short and well separate from the rest. - Keep the PWB voided of any planes/other signals in this space. - The place under the transformer should be voided as well in order to not compromise the CMR of the transformer. - ... The fact that emission decreases with STP makes me think that there is a connection between the RJ45 socket and the faceplate. SMSC had a nice application note describing ways to avoid common EMI problems with an Ethernet design. The application note is no longer on their website, but I can send it to you if you are interested. Good luck, Michael Michael Nagel Senior EMC Engineer Motorola GmbH ECC Embedded Communications Computing Lilienthalstrasse 15 85579 Neubiberg/Muenchen - Germany Ph: +49-89-9608-0 Fax: +49-89-9608-2376 e-mail: michael.na...@motorola.com info: http://www.motorola.com/computers From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of McBurney, Ian [Allen Heath UK] Sent: Freitag, 17. Juni 2005 13:17 To: emc-p...@ieee.org Subject: ethernet radiated emissions Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: ethernet radiated emissions
Ian, PCB layout is very critical; especially in the I/O area (around the RJ-45 connectors). Make sure that the Ethernet transformer you use has good common-mode filtering built in. You might also try using Bob Smith termination on the un-used pins of the I/O connector. If you've never heard of Bob Smith termination, do a google search and you can find info about it. App notes from the manufacturer of the Ethernet Phy you're using usually are a good place to start looking for recommendations related to layout. One thing I have found is that if you do use shielded cables make sure you use a cable that has 360 degree connection on the shield. Hopefully some of this helps. I'm no expert but have struggled with these same issues. Bill Fleury From: McBurney, Ian [Allen Heath UK] [mailto:ian.mcbur...@allen-heath.com] Sent: Friday, June 17, 2005 6:17 AM To: emc-p...@ieee.org Subject: ethernet radiated emissions Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: ethernet radiated emissions
No experience with Ethernet per se, so this is a very general comment. It sounds as if the emissions are common mode. If so, they may not have anything to do with the Ethernet itself, the Ethernet may be a fortuitous conductor. I would check this using a current probe around the cable, with and without Ethernet traffic. If there is little or no difference, it is ground bounce in the printed circuit board driving conducted emissions onto the Ethernet. Then you have to look at suppressing emissions from that source. From: McBurney, Ian [Allen Heath UK] ian.mcbur...@allen-heath.com List-Post: emc-pstc@listserv.ieee.org Date: Fri, 17 Jun 2005 12:17:17 +0100 To: emc-p...@ieee.org Subject: ethernet radiated emissions Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
ethernet radiated emissions
Dear colleagues; Can anyone advise me how to reduce the radiated emissions from a 100 base-T Ethernet port with a UTP cable connected to below the EN55022 class B limit? At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the emissions by 6dB. Thanks in advance; Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Radiated Emissions 1GHz
Donald I think you need to look at warranty ,current calibration and the possibility of it having to be repaired. This sounds like an older unit so will it used at one station or will it be moved about? I think it would be hard to get repaired so if it isn't going to be moved about then you probably have a solution. If its a mobile unit then you should probably invest in something a little newer. Just my own thoughts of caution. Dan Anchondo Vivotech,Inc From: owner-emc-p...@listserv.ieee.org mailto:owner-emc-p...@listserv.ieee.org]On Behalf Of Donald McElheran Sent: Wednesday, February 23, 2005 7:24 AM To: emc-p...@ieee.org Subject: Radiated Emissions 1GHz All: I am considering the purchase of a HP 8569B Spectrum analyzer for pre-compliance radiated emission measurements beyond 1GHz. The unit is a very reasonably price and would appear to be satisfactory for pre-compliance requirements. Intend to configure the SA with a Low noise 1 GHz - 18 GHz pre-amp and 1-18 GHz horn antenna. Wondering if any one on the forum had any experience with this particular SA and whether or not there are any issue which we should consider or be cautious of. Donald MCElheran Product Compliance 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Radiated Emissions 1GHz
From: Donald McElheran [ mailto:dmcelhe...@rossvideo.com] Sent: Wednesday, February 23, 2005 7:24 AM To: emc-p...@ieee.org Subject: Radiated Emissions 1GHz All: I am considering the purchase of a HP 8569B Spectrum analyzer for pre-compliance radiated emission measurements beyond 1GHz. The unit is a very reasonably price and would appear to be satisfactory for pre-compliance requirements. Intend to configure the SA with a Low noise 1 GHz - 18 GHz pre-amp and 1-18 GHz horn antenna. Wondering if any one on the forum had any experience with this particular SA and whether or not there are any issue which we should consider or be cautious of. Donald MCElheran Product Compliance Don: That analyzer should work out OK for pre-compliance testing. However, if you do plan to test all the way to 18 GHz, you might find that the typical double-ridge horn antenna has a rather high antenna factor above about 15 GHz. I stop using my EMCO 3115 at 12 GHz, where I switch over to a home-made pyramidal horn to continue up to 18 GHz. As an example, my EMCO 3115 has an antenna factor of 47.5 dB at 18 GHz, but my pyramidal horn has a factor of 35.7 dB. That 12 dB advantage helps a lot! BTW, remember to put your pre-amp at the antenna output terminal for best performance. Ed Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Is Our Specialty 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Radiated Emissions 1GHz
Donald, If you intend to use it under software control, it is not very good. You must do many things manually, including switching ranges. At most you can use software to capture scans and apply cable and antenna factors. Bob Richards. Square D. Donald McElheran dmcelhe...@rossvideo.com wrote: All: I am considering the purchase of a HP 8569B Spectrum analyzer for pre-compliance radiated emission measurements beyond 1GHz. The unit is a very reasonably price and would appear to be satisfactory for pre-compliance requirements. Intend to configure the SA with a Low noise 1 GHz - 18 GHz pre-amp and 1-18 GHz horn antenna. Wondering if any one on the forum had any experience with this particular SA and whether or not there are any issue which we should consider or be cautious of. Donald MCElheran Product Compliance 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Radiated Emissions 1GHz
All: I am considering the purchase of a HP 8569B Spectrum analyzer for pre-compliance radiated emission measurements beyond 1GHz. The unit is a very reasonably price and would appear to be satisfactory for pre-compliance requirements. Intend to configure the SA with a Low noise 1 GHz - 18 GHz pre-amp and 1-18 GHz horn antenna. Wondering if any one on the forum had any experience with this particular SA and whether or not there are any issue which we should consider or be cautious of. Donald MCElheran Product Compliance 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/listserv/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: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Card cage emissions
Laird Technologies, Chomerics Tech-Etch Products to name a few good companies that have these emi gaskets. From: McBurney, Ian [Allen Heath UK] [mailto:ian.mcbur...@allen-heath.com] Sent: Monday, January 17, 2005 6:26 AM To: emc-p...@ieee.org Subject: Card cage emissions Dear colleagues; I hope that someone may have come across this problem before. I have a 19” card cage that has rf emissions radiating from the slots between the front panels. By using a single horizontal strip of copper tape across the front of the card cage I am able to reduce the emissions considerably. My question is does anyone know of a component (like a short finger strip) that can be mounted onto the front panels or circuit boards that will bond the panels together. The bonding only needs to be in one or two positions to half the wavelength of the emissions. However the cards must be able to be removed and replaced. Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com ***LEGAL DISCLAIMER: READ THIS FIRST*** This Email and any files transmitted with it are confidential and intended solely for the use of the individual to whom or the entity to which they are addressed. If you have received this email in error please notify the sender immediately. Please note that any views or opinions presented in this email are those of the author and do not necessarily represent those of Allen Heath Limited. This email has been checked for the presence of viruses using Sophos AV Scanner. Anti-virus updates are downloaded on a daily basis . The recipient should also check this email and any attachments for the presence of viruses. Allen Heath Limited accepts no liability for any damage caused by any virus transmitted via this email. *** 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/listserv/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 Mcantwell mcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 Mcantwell mcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Card cage emissions
This is not uncommon. The solution, as you have found out, is to insure every card's panel makes contact with a neighbor, or the adjacent side card cage wall. And as you see, demonstrating the need is not all that difficult. However, actually getting people to add it is another matter. Expenses associated with even a small tooling change may make it undesirable to modify cheaper, lower-profit cards. Also, legacy cards made to looser tolerances may not fit into assemblies of later, better grounded and shielded cards. On top of this, other practical issues must be considered: Will fingerstock survive manufacturing and shipping? Will it fit into shipping containers? Might fingerstock cut or scratch people adding it or packing cards, or even end-users on whose cards it is mounted? Will it stay put and not fall off? Does it compromise ventilation, fire containment or sealing? Lately, is it properly recyclable? Right-angle, clip-on contact fingerstock may be had. Installed opposite each other, it might work. Fingers tend to fall off easily, can prevent use of existing shipping boxes, are time consuming to add, if installed singly must be tightly controlled as to location, are either easily damaged or prone to scratch users, and may be suspect for disposal. The final cost may be more than you want to spend. These materials are best used along the whole edge of cards, with panels designed to accept and mate with them. My experience suggests that adding card-edge grounding is therefore most easily done for a *new* product -- and that companies who don't have this problem already use it. Cortland Richmond Ian McBurney asked: My question is does anyone know of a component (like a short finger strip) that can be mounted onto the front panels or circuit boards that will bond the panels together. The bonding only needs to be in one or two positions to half the wavelength of the emissions. However the cards must be able to be removed and replaced. 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/listserv/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 Mcantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Card cage emissions
Ian, A great deal will depend on the design of the card cage itself and on the manufacturer. In the past I have found that card cage products manufactured by Schroff were among the best featured for EMI control, with some useful BeCu strips available as an add-on kit. Their understanding of the issues was better than many others, and they even publish test reports for some of their enclosure products. It is also vital that the panels are not anodised aluminium, but some conductive finish. Often products are available with alternative finishes, so you need to ensure that you select the right one. Best regards, Neil R. Barker C.Eng. MIEE FSEE MIEEE Manager Compliance Engineering e2v technologies (uk) ltd 106 Waterhouse Lane Chelmsford Essex CM1 2QU UK Tel: +44 (0)1245 453616 Fax: +44 (0)1245 453410 e-mail: neil.bar...@e2v.com Web: http://www.e2v.com http://www.e2v.com/ From: McBurney, Ian [Allen Heath UK] [mailto:ian.mcbur...@allen-heath.com] Sent: 17 January 2005 14:26 To: emc-p...@ieee.org Subject: Card cage emissions Dear colleagues; I hope that someone may have come across this problem before. I have a 19 card cage that has rf emissions radiating from the slots between the front panels. By using a single horizontal strip of copper tape across the front of the card cage I am able to reduce the emissions considerably. My question is does anyone know of a component (like a short finger strip) that can be mounted onto the front panels or circuit boards that will bond the panels together. The bonding only needs to be in one or two positions to half the wavelength of the emissions. However the cards must be able to be removed and replaced. Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com 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/listserv/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 Mcantwell mcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Card cage emissions
Ian, Instrument Specialties in the US may have something. Josh McBurney, Ian [Allen Heath UK] wrote: Dear colleagues; I hope that someone may have come across this problem before. I have a 19” card cage that has rf emissions radiating from the slots between the front panels. By using a single horizontal strip of copper tape across the front of the card cage I am able to reduce the emissions considerably. My question is does anyone know of a component (like a short finger strip) that can be mounted onto the front panels or circuit boards that will bond the panels together. The bonding only needs to be in one or two positions to half the wavelength of the emissions. However the cards must be able to be removed and replaced. Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com ***LEGAL DISCLAIMER: READ THIS FIRST*** This Email and any files transmitted with it are confidential and intended solely for the use of the individual to whom or the entity to which they are addressed. If you have received this email in error please notify the sender immediately. Please note that any views or opinions presented in this email are those of the author and do not necessarily represent those of Allen Heath Limited. This email has been checked for the presence of viruses using Sophos AV Scanner. Anti-virus updates are downloaded on a daily basis . The recipient should also check this email and any attachments for the presence of viruses. Allen Heath Limited accepts no liability for any damage caused by any virus transmitted via this email. *** 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/listserv/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 Mcantwell mcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc -- Josh Wiseman CE Lab Manager, L F Research 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/listserv/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 Mcantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Card cage emissions
Dear colleagues; I hope that someone may have come across this problem before. I have a 19” card cage that has rf emissions radiating from the slots between the front panels. By using a single horizontal strip of copper tape across the front of the card cage I am able to reduce the emissions considerably. My question is does anyone know of a component (like a short finger strip) that can be mounted onto the front panels or circuit boards that will bond the panels together. The bonding only needs to be in one or two positions to half the wavelength of the emissions. However the cards must be able to be removed and replaced. Ian McBurney. Allen Heath Limited. email: ian.mcbur...@allen-heath.com ***LEGAL DISCLAIMER: READ THIS FIRST*** This Email and any files transmitted with it are confidential and intended solely for the use of the individual to whom or the entity to which they are addressed. If you have received this email in error please notify the sender immediately. Please note that any views or opinions presented in this email are those of the author and do not necessarily represent those of Allen Heath Limited. This email has been checked for the presence of viruses using Sophos AV Scanner. Anti-virus updates are downloaded on a daily basis . The recipient should also check this email and any attachments for the presence of viruses. Allen Heath Limited accepts no liability for any damage caused by any virus transmitted via this email. *** 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/listserv/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 Mcantwell mcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Extension of the DFS requirement for UNII, BPL publication i n the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD
Don, The EMC Directive comes into force on 20 July 2007. National regulators have until 20 January 2007 to amend their national regulations to align with 2004/108/EC. No impact on industry until 2007, and then there is a two year transition period (to 20 July 2009). I don’t expect any changes in the harmonized standards, other than that the list will reference 2004/108/EC, rather than 89/336/EEC. Ghery S. Pettit Intel Corporation _ From: owner-emc-p...@listserv.ieee.org mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of djumbdenst...@tycoint.com Sent: Wednesday, January 12, 2005 10:56 AM To: emc-p...@ieee.org Subject: FW: Extension of the DFS requirement for UNII, BPL publication i n the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD Hello Group, The new EMC Directive comes into force on Jan 20, 2005. Does anyone know if harmonized standards have been developed in support of the changes in the directive? See Item 4 below for more information. Best regards, Don Umbdenstock Tyco Safety Products/Sensormatic _ From: Sid Sanders [mailto:s...@timco.cc] Sent: Tuesday, January 11, 2005 1:09 PM To: s...@timco.cc Subject: Extension of the DFS requirement for UNII, BPL publication in the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD TIMCO ENGINEERING INC. TCB FCB 849 NW State Road 45 FCC Approvals Newberry, Florida 32669 Industry Canada Approvals http://www.timcoengr.com http://www.timcoengr.com/ Notified Body for Europe 888.472.2424 F 352.472.2030 email: t...@timcoengr.com January 10, 2005 SUBJECT: Extension of the DFS requirement for UNII, BPL publication in the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD Hi, Here are some updates: 1/ FCC - Mandatory DFS requirement for UNII device on January 20, 2005: “Dynamic Frequency Selection (DFS) Requirements Mandatory All UNII device approved after January 20, 2005, must comply with the dynamic frequency selection (DFS) requirements in accordance with the adopted rules. See Section 15.37(l) of the FCC Rules. However, as of this date, the Commission and NTIA have not agreed to a suitable test procedure for determining compliance with these requirements. Manufacturers are getting nervous that no UNII devices will be able to be approved after January 20, 2005. This note is to reassure everyone that an extension is in the works. The Commission has no plans to discontinue Certification of UNII devices for the 5250 - 5350 MHz band that do not have DFS capability. If the item granting the extension is approved by the Commission by January 20, business will continue as usual. However if the Commission approval does not happen by January 20, the Lab may develop a grant Note Code to indicate that an extension is imminent and we are granting a UNII device based on the predicted extension. 2/ BPL: The new rules, FCC 04-245 (ET Docket No. 04-37), were published in the Federal Register on January 7, 2005. http://a2 7.g.akamaitech.net/7/257/2422/01jan2005 800/edocket.access.gpo.gov/2005/pdf/05-246.pdf The application of the new rules is effective on February 7, 2005. 3/ OET clarifies measurement of Broadband Emissions: The Public Notice DA: 04-3946 was released on December 17, 2004. This PN clarifies the measurement of extremely narrow pulses generating wideband emissions, other than UWB emissions, using a pulse desensitization correction factor (PDCF). This document can be downloaded from our website, http://www.timcoengr.com/Download/FCC/DA-04-3946A1--PDCF.pdf 4/ New EMCD 2004/108/EC: It was published in the OJ of the EU on 12/31/2004: http://europa.eu.int/eur-lex/lex/LexUri erv/site/en/oj/2004/l_390/l_39020041231en00240037.pdf It looks like the implementation dates are as follows: - Entry into force: January 20, 2005 - Repeal date for 89/336/EEC: July 20, 2007 - Transitional provisions: For devices compliant with 89/336/EEC and marketed before July 20, 2009. 5/ New Automotive EMC Directive 2004/104/EC: It was published in the OJ of the EU on 11/13/2004. Relevant information concerning the overlapping of the EMC and RTTE Directives for after market devices (e.g. LMR, etc.) can be found in section 3.2.9. It appears that testing and type approval are no longer required for devices that are not related to “immunity-related” functions. Now this is only a paperwork matter that still requires the involvement of technical service (EU appointed agency) to determine if the device is “immunity-related” or not. Please contact us, as we are used
FW: Extension of the DFS requirement for UNII, BPL publication i n the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD
This is a multi-part message in MIME format. Hello Group, The new EMC Directive comes into force on Jan 20, 2005. Does anyone know if harmonized standards have been developed in support of the changes in the directive? See Item 4 below for more information. Best regards, Don Umbdenstock Tyco Safety Products/Sensormatic _ From: Sid Sanders [mailto:s...@timco.cc] Sent: Tuesday, January 11, 2005 1:09 PM To: s...@timco.cc Subject: Extension of the DFS requirement for UNII, BPL publication in the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD TIMCO ENGINEERING INC. TCB FCB 849 NW State Road 45 FCC Approvals Newberry, Florida 32669 Industry Canada Approvals http://www.timcoengr.com http://www.timcoengr.com/ Notified Body for Europe 888.472.2424 F 352.472.2030 email: t...@timcoengr.com January 10, 2005 SUBJECT: Extension of the DFS requirement for UNII, BPL publication in the Federal Register, OET clarifies measurement of Broadband emissions, new EMCD, new Automotive EMCD Hi, Here are some updates: 1/ FCC - Mandatory DFS requirement for UNII device on January 20, 2005: “Dynamic Frequency Selection (DFS) Requirements Mandatory All UNII device approved after January 20, 2005, must comply with the dynamic frequency selection (DFS) requirements in accordance with the adopted rules. See Section 15.37(l) of the FCC Rules. However, as of this date, the Commission and NTIA have not agreed to a suitable test procedure for determining compliance with these requirements. Manufacturers are getting nervous that no UNII devices will be able to be approved after January 20, 2005. This note is to reassure everyone that an extension is in the works. The Commission has no plans to discontinue Certification of UNII devices for the 5250 - 5350 MHz band that do not have DFS capability. If the item granting the extension is approved by the Commission by January 20, business will continue as usual. However if the Commission approval does not happen by January 20, the Lab may develop a grant Note Code to indicate that an extension is imminent and we are granting a UNII device based on the predicted extension. 2/ BPL: The new rules, FCC 04-245 (ET Docket No. 04-37), were published in the Federal Register on January 7, 2005. http://a2 7.g.akamaitech.net/7/257/2422/01jan2005 800/edocket.access.gpo.gov/2005/pdf/05-246.pdf The application of the new rules is effective on February 7, 2005. 3/ OET clarifies measurement of Broadband Emissions: The Public Notice DA: 04-3946 was released on December 17, 2004. This PN clarifies the measurement of extremely narrow pulses generating wideband emissions, other than UWB emissions, using a pulse desensitization correction factor (PDCF). This document can be downloaded from our website, http://www.timcoengr.com/Download/FCC/DA-04-3946A1--PDCF.pdf 4/ New EMCD 2004/108/EC: It was published in the OJ of the EU on 12/31/2004: http://europa.eu.int/eur-lex/lex/LexUri erv/site/en/oj/2004/l_390/l_39020041231en00240037.pdf It looks like the implementation dates are as follows: - Entry into force: January 20, 2005 - Repeal date for 89/336/EEC: July 20, 2007 - Transitional provisions: For devices compliant with 89/336/EEC and marketed before July 20, 2009. 5/ New Automotive EMC Directive 2004/104/EC: It was published in the OJ of the EU on 11/13/2004. Relevant information concerning the overlapping of the EMC and RTTE Directives for after market devices (e.g. LMR, etc.) can be found in section 3.2.9. It appears that testing and type approval are no longer required for devices that are not related to “immunity-related” functions. Now this is only a paperwork matter that still requires the involvement of technical service (EU appointed agency) to determine if the device is “immunity-related” or not. Please contact us, as we are used to work with a EU Agency that has an office in the USA. 6/ Extention of 25kHz for Part 90: This Memorandum appears to stay the January 1, 2005 deadline for 25kHz BW Transmitters in the 150-174 421-512MHz PLMR bands. The complete docket can be downloaded from our website, htt ://www.timcoengr.com/Download/FCC/FCC-0 -292A1_WTDocket99_87_3rd_MOO_25kHz_Extention.pdf . It appears that the deadline is postponed until this Third MOO is resolved. If you are involved I recommend that you read the complete text of this report. If you want to be removed from this distribution please let me know. Best Regards, Sid Sanders Bruno Clavier S:\TIMCO\Newsletter\newsltr50110.doc This message
RE: Conducted Emissions PK vs AVG
As I understand it, an AVG Detector is just a 1st order, low-pass RC filter after the IF amp and detector. The Video Averaging provided by the HP8568B and perhaps others, is a weighted average of successive video trace data. For a CW signal (a periodic waveform) the AVG and PK detectors should show the same amplitude. However, the AVG detector attenuates incoherent or non-periodic signals and the attenuation depends on the pulse rep rate. Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. From: Brent DeWitt [mailto:bdew...@ix.netcom.com] Sent: December 18, 2004 8:02 PM To: Ken Javor; Ralph McDiarmid; ieee pstc list Subject: RE: Conducted Emissions PK/AVG Your point is well taken Ken, and this certainly is interesting. My approach to the concept of average does indeed run afoul of the limitations of measurement devices and the potential for instrument dependent results. To the best of my knowledge, the FCC is the most ill-defined with respect to the averaging time constant. That is what initially lead me to my stated empirical method. Other thoughts are welcomed! Brent 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Conducted Emissions PK/AVG
I assume the time-constant of the AVG Detector is specific in CISPR 16 and that this standard is called out in FCC Part 15. I think if the VBW was placed before the LOG amplifier in the signal chain, it would yield the correct response. If placed after the LOG amp, the BW limit would not provide the desired effect. The UL EMC software we use has tick-boxes for AVG detection, but they have no noticeable affect on the receiver actions nor on the screen plot. Updated versions of this program from UL have also failed to provide a AVG detection function. It could be that this is not available on our 8568B. So, in the rather rare instance where we need to do an AVG conducted scan, we simply reduce the VBW in the test setup file to 10Hz. Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. From: Brent DeWitt [mailto:bdew...@ix.netcom.com] Sent: December 18, 2004 8:02 PM To: Ken Javor; Ralph McDiarmid; ieee pstc list Subject: RE: Conducted Emissions PK/AVG Your point is well taken Ken, and this certainly is interesting. My approach to the concept of average does indeed run afoul of the limitations of measurement devices and the potential for instrument dependent results. To the best of my knowledge, the FCC is the most ill-defined with respect to the averaging time constant. That is what initially lead me to my stated empirical method. Other thoughts are welcomed! Brent -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ken Javor Sent: Friday, December 17, 2004 8:14 PM To: bdew...@ix.netcom.com; Ralph McDiarmid; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Now this is getting interesting. If you arbitrarily reduce the VBW until you see no time dependent amplitude variation, I think that leads to non-repeatability. That is, if my spectrum analyzer has a 1 Hz VBW, and yours has a 10 Hz VBW, we could get different answers. At least at one time, there was a specified time interval over which the averaging was to occur, which is another way of saying the the video bandwidth was specified. I think the idea of average detection is to be able to get an accurate assessment of the value of a cw or near cw (AM) signal, possibly in the presence of broadband noise. Considering that pulsed cw was considered by the military to be a narrow-band signal, it would seem that the specific averaging time period would be very important. On the other hand, MIL-STD-461 has for almost forty years required peak detection of all signals, whether NB or BB. Go figure. I'm rambling on, but the point I am trying to make is that I believe average detection should have an associated time constant, somehow relating to the information content of the communication link protected by the radiated emission limit in question. From: Brent DeWitt bdew...@ix.netcom.com Reply-To: bdew...@ix.netcom.com Date: Fri, 17 Dec 2004 18:39:11 -0800 To: Ralph McDiarmid ralph.mcdiar...@xantrex.com, ieee pstc list emc-p...@ieee.org Subject: RE: Conducted Emissions PK/AVG Hi Ralph, The HP 8568 and 8566 have a video averaging function, which averages multiple digital traces (up to 100 if I remember correctly). It can be used in conjunction with a narrow VBW to get very close to a true average measurement. I've always been rather empirical about the averaging criterion. On a spectrum analyzer in zero span and linear detection, I simply reduce the VBW and possibly add video averaging until I don't see any more variation in the screen trace and call it done. Brent G DeWitt Laboratory Manager CKC Laboratories Redmond, WA email: brent.dew...@ckc.com phone: 425-883-4757 cell: 425-417-8228 -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ralph McDiarmid Sent: Friday, December 17, 2004 11:51 AM To: ieee pstc list Subject: RE: Conducted Emissions PK/AVG I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say
RE: Conducted Emissions PK/AVG
Sorry to post a second response, but I hit send before I finished my thoughts. Ken's stated concept of the rational of averaging is a bit different from mine. This may be a MIL vs. FCC background related thing (me being the latter). I've always viewed the FCC's switch to average detection above 1GHz as more of a rough approximation to a spectral density measurement. If my approach is correct, the idea is that receivers of potential interference above 1GHz have relatively wide resolution bandwidths, and that something closer to the 1MHz RBW in combination with an average detector could measure the annoyance factor. Again, other thoughts are welcomed! Brent -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ken Javor Sent: Friday, December 17, 2004 8:14 PM To: bdew...@ix.netcom.com; Ralph McDiarmid; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Now this is getting interesting. If you arbitrarily reduce the VBW until you see no time dependent amplitude variation, I think that leads to non-repeatability. That is, if my spectrum analyzer has a 1 Hz VBW, and yours has a 10 Hz VBW, we could get different answers. At least at one time, there was a specified time interval over which the averaging was to occur, which is another way of saying the the video bandwidth was specified. I think the idea of average detection is to be able to get an accurate assessment of the value of a cw or near cw (AM) signal, possibly in the presence of broadband noise. Considering that pulsed cw was considered by the military to be a narrow-band signal, it would seem that the specific averaging time period would be very important. On the other hand, MIL-STD-461 has for almost forty years required peak detection of all signals, whether NB or BB. Go figure. I'm rambling on, but the point I am trying to make is that I believe average detection should have an associated time constant, somehow relating to the information content of the communication link protected by the radiated emission limit in question. From: Brent DeWitt bdew...@ix.netcom.com Reply-To: bdew...@ix.netcom.com Date: Fri, 17 Dec 2004 18:39:11 -0800 To: Ralph McDiarmid ralph.mcdiar...@xantrex.com, ieee pstc list emc-p...@ieee.org Subject: RE: Conducted Emissions PK/AVG Hi Ralph, The HP 8568 and 8566 have a video averaging function, which averages multiple digital traces (up to 100 if I remember correctly). It can be used in conjunction with a narrow VBW to get very close to a true average measurement. I've always been rather empirical about the averaging criterion. On a spectrum analyzer in zero span and linear detection, I simply reduce the VBW and possibly add video averaging until I don't see any more variation in the screen trace and call it done. Brent G DeWitt Laboratory Manager CKC Laboratories Redmond, WA email: brent.dew...@ckc.com phone: 425-883-4757 cell: 425-417-8228 -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ralph McDiarmid Sent: Friday, December 17, 2004 11:51 AM To: ieee pstc list Subject: RE: Conducted Emissions PK/AVG I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas
RE: Conducted Emissions PK/AVG
Your point is well taken Ken, and this certainly is interesting. My approach to the concept of average does indeed run afoul of the limitations of measurement devices and the potential for instrument dependent results. To the best of my knowledge, the FCC is the most ill-defined with respect to the averaging time constant. That is what initially lead me to my stated empirical method. Other thoughts are welcomed! Brent -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ken Javor Sent: Friday, December 17, 2004 8:14 PM To: bdew...@ix.netcom.com; Ralph McDiarmid; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Now this is getting interesting. If you arbitrarily reduce the VBW until you see no time dependent amplitude variation, I think that leads to non-repeatability. That is, if my spectrum analyzer has a 1 Hz VBW, and yours has a 10 Hz VBW, we could get different answers. At least at one time, there was a specified time interval over which the averaging was to occur, which is another way of saying the the video bandwidth was specified. I think the idea of average detection is to be able to get an accurate assessment of the value of a cw or near cw (AM) signal, possibly in the presence of broadband noise. Considering that pulsed cw was considered by the military to be a narrow-band signal, it would seem that the specific averaging time period would be very important. On the other hand, MIL-STD-461 has for almost forty years required peak detection of all signals, whether NB or BB. Go figure. I'm rambling on, but the point I am trying to make is that I believe average detection should have an associated time constant, somehow relating to the information content of the communication link protected by the radiated emission limit in question. From: Brent DeWitt bdew...@ix.netcom.com Reply-To: bdew...@ix.netcom.com Date: Fri, 17 Dec 2004 18:39:11 -0800 To: Ralph McDiarmid ralph.mcdiar...@xantrex.com, ieee pstc list emc-p...@ieee.org Subject: RE: Conducted Emissions PK/AVG Hi Ralph, The HP 8568 and 8566 have a video averaging function, which averages multiple digital traces (up to 100 if I remember correctly). It can be used in conjunction with a narrow VBW to get very close to a true average measurement. I've always been rather empirical about the averaging criterion. On a spectrum analyzer in zero span and linear detection, I simply reduce the VBW and possibly add video averaging until I don't see any more variation in the screen trace and call it done. Brent G DeWitt Laboratory Manager CKC Laboratories Redmond, WA email: brent.dew...@ckc.com phone: 425-883-4757 cell: 425-417-8228 -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ralph McDiarmid Sent: Friday, December 17, 2004 11:51 AM To: ieee pstc list Subject: RE: Conducted Emissions PK/AVG I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http
Re: Conducted Emissions PK/AVG
Now this is getting interesting. If you arbitrarily reduce the VBW until you see no time dependent amplitude variation, I think that leads to non-repeatability. That is, if my spectrum analyzer has a 1 Hz VBW, and yours has a 10 Hz VBW, we could get different answers. At least at one time, there was a specified time interval over which the averaging was to occur, which is another way of saying the the video bandwidth was specified. I think the idea of average detection is to be able to get an accurate assessment of the value of a cw or near cw (AM) signal, possibly in the presence of broadband noise. Considering that pulsed cw was considered by the military to be a narrow-band signal, it would seem that the specific averaging time period would be very important. On the other hand, MIL-STD-461 has for almost forty years required peak detection of all signals, whether NB or BB. Go figure. I'm rambling on, but the point I am trying to make is that I believe average detection should have an associated time constant, somehow relating to the information content of the communication link protected by the radiated emission limit in question. From: Brent DeWitt bdew...@ix.netcom.com Reply-To: bdew...@ix.netcom.com Date: Fri, 17 Dec 2004 18:39:11 -0800 To: Ralph McDiarmid ralph.mcdiar...@xantrex.com, ieee pstc list emc-p...@ieee.org Subject: RE: Conducted Emissions PK/AVG Hi Ralph, The HP 8568 and 8566 have a video averaging function, which averages multiple digital traces (up to 100 if I remember correctly). It can be used in conjunction with a narrow VBW to get very close to a true average measurement. I've always been rather empirical about the averaging criterion. On a spectrum analyzer in zero span and linear detection, I simply reduce the VBW and possibly add video averaging until I don't see any more variation in the screen trace and call it done. Brent G DeWitt Laboratory Manager CKC Laboratories Redmond, WA email: brent.dew...@ckc.com phone: 425-883-4757 cell: 425-417-8228 -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ralph McDiarmid Sent: Friday, December 17, 2004 11:51 AM To: ieee pstc list Subject: RE: Conducted Emissions PK/AVG I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Conducted Emissions PK/AVG
Hi Ralph, The HP 8568 and 8566 have a video averaging function, which averages multiple digital traces (up to 100 if I remember correctly). It can be used in conjunction with a narrow VBW to get very close to a true average measurement. I've always been rather empirical about the averaging criterion. On a spectrum analyzer in zero span and linear detection, I simply reduce the VBW and possibly add video averaging until I don't see any more variation in the screen trace and call it done. Brent G DeWitt Laboratory Manager CKC Laboratories Redmond, WA email: brent.dew...@ckc.com phone: 425-883-4757 cell: 425-417-8228 -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Ralph McDiarmid Sent: Friday, December 17, 2004 11:51 AM To: ieee pstc list Subject: RE: Conducted Emissions PK/AVG I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. -Original Message- From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Conducted Emissions PK/AVG
I suggest there is an important distinction between video averaging and average detection using limited VBW. If this is correct, can someone enlighten those of us who are unsure? Ralph McDiarmid, ASc Compliance Engineering Group Xantrex Technology Inc. From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of Cortland Richmond Sent: December 16, 2004 1:04 PM To: Alex McNeil; ieee pstc list Subject: Re: Conducted Emissions PK/AVG Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Conducted Emissions PK/AVG
Alex McNeil asked: Is the problem that the Test House may have used AVG BW 30KHz and this should have been AVG BW 9KHz the problem Sure looks like it from what you posted. There've been discussions here -- it comes up every so often -- how to to do averaging on a SA. Without knowing how they did, it's hard to say for sure, but it looks like you are close enough to hit the target with a hand grenade anyway. But are you sure it doesn't say 30 *Hz*? Narrowing the bandwidth 'way down is a method used to get averaging on a SA. (I will speculate that someone might have learned to -- incorrectly -- use video averaging in dB mode then increase BW to compensate for the error that causes.) Cortland Richmond 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Conducted Emissions PK/AVG
scale set to LOG, OOPS, that should have been LINEAR Sorry. Bob Richards b...@toprudder.com wrote: Alex, It is very common that the emissions plots will be made with the RBW and VBW that you mentioned. The actual QP and AV measurements should have the instrument set with the appropriate detector and bandwidths. The RBW should always be 9kHz, and for the average measurement the VBW should be significantly lower than the pulse repetition frequency, the detector should be SAMPLE, scale set to LOG, etc. Also, the frequency span should be set to zero for a compliance measurement. I've seen commercial automated software that does a very poor job of this. Bob Richards, NCT Square D. Alex McNeil alex.mcn...@ingenico.co.uk wrote: Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Conducted Emissions PK/AVG
Alex, It is very common that the emissions plots will be made with the RBW and VBW that you mentioned. The actual QP and AV measurements should have the instrument set with the appropriate detector and bandwidths. The RBW should always be 9kHz, and for the average measurement the VBW should be significantly lower than the pulse repetition frequency, the detector should be SAMPLE, scale set to LOG, etc. Also, the frequency span should be set to zero for a compliance measurement. I've seen commercial automated software that does a very poor job of this. Bob Richards, NCT Square D. Alex McNeil alex.mcn...@ingenico.co.uk wrote: Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Conducted Emissions PK/AVG
Alex, You are on the right track. However, even a VBW of 9 kHz will not yield a true average measurement in this frequency range. First of all, it is not likely that the spectrum analyzer meets CISPR requirements as a test receiver. Second, using video averaging as a substitute for an actual average detector requires a VBW that is significantly less than the RBW, and the amplitude scale must be linear instead of log (the average of the log is different than the average). This is a highlight of the most important settings - CISPR 16 will have the detailed requirements from which suitable and/or reasonable instrument settings can be determined. It is not surprising to hear of these differences - the receiver measurement definitely takes precedence over the spectrum analyzer. Thanks, Mike From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf Of Alex McNeil Sent: Thursday, December 16, 2004 8:19 AM To: emc-p...@ieee.org Subject: Conducted Emissions PK/AVG Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX This email has been scanned for all known viruses and appropriate content by the Messagelabs mail service. 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Conducted Emissions PK/AVG
Are you sure it says AVG BW 30kHz, and not AVG BW 30 Hz? Is this a typo? Also, quasi-peak should always be at or below the peak measurement. This is why a peak measurement can be made (quickly) and compared to the quasi-peak limit line, and if all the peaks are below the quasi-peak limit, the measurement is a pass. If you have quasi-peak measurements higher than the peaks measurements, then either something is wrong with the test equipment/software, or the emissions of the EUT changed between the time the two measurements were made. Don Borowski Schweitzer Engineering Labs Pullman, WA, USA Alex McNeil alex.mcn...@ingenico.co.uk wrote on 12/16/2004 08:19:08 AM: Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Conducted Emissions PK/AVG
Hi Guys, I had a product tested that failed the conducted emissions. The switch mode power supply was the problem. It runs at approx. 200KHz. The failed readings were in the 150KHz to 600KHz band. The peaks were over the Avg and below the QPk, so the Avg test was done. This resulted in the failures. However, after close examination of the Test lab results, the printout showed IF BW 9KHz AND AVG BW 30KHz below the graphical and tabulated results. The tests were done on a SA. I have a receiver here and my test results for PK are the same as the Test Lab but for the Avg my test results are significantly lower than the Test House. Is the problem that the Test House may have used “AVG BW 30KHz” and this should have been “AVG BW 9KHz” the problem or am I missing something here? Thank you for your time, it is always appreciated. Kind Regards ALEX This email has been scanned for all known viruses and appropriate content by the Messagelabs mail service. 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/listserv/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 For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Radiated Emissions - Oscillator issue
Carl Richards posted: Before I rush off back to development, I wondered if anyone in the group had any advice about implementing small areas of ground plane directly underneath oscillators ? I'm going to request upper and lower ground planes with via stitching between them and our internal groundplane. The oscillator is a 4pin plastic packaged device. Is there anything else or experience that anyone Yes, it's the same as applying copper tape there -- if there is the same, direct path for current induced in the shield/tape to get back to the source. However, if you are putting Cu tape from the board to the chassis, that's a different barrel of monkeys; getting a consistent card-to-cage ground at high frequencies is not easy - and sometimes a card cage isn't a good ground, either, as you'll see if you model a shelf as a slot radiator. Cortland Richmond 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Radiated Emissions - Oscillator issue
Dear Group, We're working on a next Rev of board on our system and we're having a problem with a 66MHz oscillator during radiated emissions testing. The board slides vertically into a shelf(aka the card cage). The solder side of the board is approx 1/4 from a plated steel vertical which is one of the shelf ends. Our problem is that when the card is inserted in slot 1 a harmonic of the 66MHz is leaving the card cage from the small gap between card and the shelf end. Covering the small gap with CU tape cures the emission problem. Various experiments with foil and CU tape have established that shielding the solder side directly underneath the oscillator yields considerable improvement. Moving the card away from the shelf end into higher slot numbers reduces emissions considerably. Before I rush off back to development, I wondered if anyone in the group had any advice about implementing small areas of ground plane directly underneath oscillators ? I'm going to request upper and lower ground planes with via stitching between them and our internal groundplane. The oscillator is a 4pin plastic packaged device. Is there anything else or experience that anyone else in the group can pass on this subject. Many thanks Carl Carl Richards, Regulatory Compliance Manager, Aspect Communications E-mail carl.richa...@aspect.com Tel +44 (0)208 589 1461 Fax +44 (0)870 460 1950 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Using TEM cells for radiated emissions at 30MHz
Hi Pat - You might be interested in a presentation on this very subject (albeit using a GTEM) that was presented at one of our EMC Society meetings last year. Go to http://www.ieee.org/rmcemc and click on archives. Look for the May 20th 2003 link and download the paper titled : Prediction not Correlation by Matt Aschenberg. This presentation morphed into a full blown paper recently published in the IEEE 2004 Conference proceedings. Best Regards Charles Grasso Senior Compliance Engineer Echostar Communications Corp. Tel: 303-706-5467 Fax: 303-799-6222 Cell: 303-204-2974 Email: charles.gra...@echostar.com; mailto:charles.gra...@echostar.com; Email Alternate: chasgra...@ieee.org From: Diethard Hansen [mailto:euro.emc.serv...@swissonline.ch] Sent: Thursday, November 18, 2004 5:44 AM To: pat_law...@condordc.com; emc-p...@ieee.org Subject: RE: Using TEM cells for radiated emissions at 30MHz Hi Pat, May be it helps reading through the literature on our web ( www.euro-emc-service.de ) with hints to our inventions like GTEM (end of 80s), EUROTEM (End of 90s) etc, plus background (RD-web-section) info. A size limited TEM device can not do everything but may sometimes prove useful. Detailed info also in IEC 61000-20. TEM Devices for radiated emission and immunity.The basic idea is to consider a free space (TEM-basically only mode) wave inside and for emissions use the concept of t o t a l radiated power to correlate to OATS.This requires EUT mechanical rotations in a GTEM (Dr. Perry F. Wilson Algorithm- now working for NIST Bolder Co--He also published an article I think in IEEE EMC Transaction How to correlate below 30 MHz several years ago (mid 90s?) ). At the Apex you receive (based on simple e.g. 3, x-y-z orientation of EUT) voltages vs. frequency to feed into the software correlation algorithm. To be more specific we need to hear details of the product (EUT), in particular size! Cables do also matter! One TEM cell competitor is e.g. compact chambers now. What TEM type of cell are you considering? Regulatory compliance/acceptance under EN 55022/ CISPR 22 issues (accreditation?) may also be an important issue. IEC 61000-20 is just a new basic standard.normative references? The GTEM is listed in the new ANSI/IEEE C 63.4. Diethard Best regards Dr. Diethard Hansen EES President, Principal Consultant, Trainer US Senior NARTE certif. EMC Eng. 001937NE EMC+Automotive+Telecom QM+techn. EA-Auditor Euro EMC SERVICE (EES) Dr.-Ing. D. Hansen POB 64, Bahnhofstr.39, CH-8965 Berikon 2, Switzerland, Swiss VAT (Mwst.)No.:323214 tel./fax: +41 566 33 73 81 German mobile phone: +49(0)1736015909 www.euro-emc-service.de euro.emc.serv...@swissonline.ch ( mailto:diethard.han...@ieee.org) Consulting+Seminars+RD-Projects Marketing+CE-Testing+ww.Audits From: owner-emc-p...@listserv.ieee.org mailto:owner-emc-p...@listserv.ieee.org]On Behalf Of pat_law...@condordc.com Sent: Mittwoch, 17. November 2004 20:19 To: emc-p...@ieee.org Subject: Using TEM cells for radiated emissions at 30MHz Hi: I was given some literature by management recently advertising the use of a TEM cell for radiated emissions: http://www.wavecontrol.com/index2004.php?idioma=2 Our people have the impression that a TEM cell small enough to fit on a table-top could eliminate the need to go to the local OATS. I don't think it's that simple, but I need more solid information. The products I test are component power supplies, using CISPR 22 Class A Class B limits. Most of our emissions are in the range of 30-100MHz. 1) I've heard TEM cells need correlation to an OATS. Is this a one-time correlation (like a calibration), or is it tied to the model being tested? 2) The dimensions of the TEM cell appear small compared to a wavelength at 30MHz. Does the issue of near-field and far-field zones still apply in a TEM cell? If so, how do you correlate the two? 3) The product appears to have pyramid absorbers inside (no reverberation). Does this mean the EUT needs to be repositioned several times during the test? 4) How do the TEM cell correlation factors and noise floor of the spectrum analyzer interact? Do I need a certain maximum noise floor in order to make measurements? I guess I'm looking for a TEM cell tutorial, or maybe a book or paper titled 'TEM Cells For Dummies'. I wrote to the vendor, but they haven't responded. On a slightly different note, has there been any progress for accepting emissions measurements from reverberation chambers (IEC 61000-4-21)? Thanks in advance, Pat Lawler EMC Engineer Condor DC Power Supplies, Inc. --- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org
RE: Using TEM cells for radiated emissions at 30MHz
Pat, May I suggest that you contact... Steven Burger (512) 657-6147 temconsult...@aol.com He is a private consultant that could probably steer you in the right direction ( no fee for directions, I guess ) . Regards, Reg Henry QA / Electrical Engineering FCC CE UL Compliance Engineer Vicon Industries 89 Arkay Dr. Hauppauge, New York 11788 *Tel: (631) 952-2288 x310 *Fax: (631) 951-2288 *Web: http://www.vicon-cctv.com/ This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. The company accepts no liability for any damage caused by any virus transmitted by this email. Furthermore, the company does not warrant a proper and complete transmission of this information, nor does it accept liability for any delays. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. From: pat_law...@condordc.com [mailto:pat_law...@condordc.com] Sent: Wednesday, November 17, 2004 2:19 PM To: emc-p...@ieee.org Subject: Using TEM cells for radiated emissions at 30MHz Hi: I was given some literature by management recently advertising the use of a TEM cell for radiated emissions: http://www.wavecontrol.com/index2004.php?idioma=2 Our people have the impression that a TEM cell small enough to fit on a table-top could eliminate the need to go to the local OATS. I don't think it's that simple, but I need more solid information. The products I test are component power supplies, using CISPR 22 Class A Class B limits. Most of our emissions are in the range of 30-100MHz. 1) I've heard TEM cells need correlation to an OATS. Is this a one-time correlation (like a calibration), or is it tied to the model being tested? 2) The dimensions of the TEM cell appear small compared to a wavelength at 30MHz. Does the issue of near-field and far-field zones still apply in a TEM cell? If so, how do you correlate the two? 3) The product appears to have pyramid absorbers inside (no reverberation). Does this mean the EUT needs to be repositioned several times during the test? 4) How do the TEM cell correlation factors and noise floor of the spectrum analyzer interact? Do I need a certain maximum noise floor in order to make measurements? I guess I'm looking for a TEM cell tutorial, or maybe a book or paper titled 'TEM Cells For Dummies'. I wrote to the vendor, but they haven't responded. On a slightly different note, has there been any progress for accepting emissions measurements from reverberation chambers (IEC 61000-4-21)? Thanks in advance, Pat Lawler EMC Engineer Condor DC Power Supplies, Inc. --- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Using TEM cells for radiated emissions at 30MHz
Hi Pat, May be it helps reading through the literature on our web ( www.euro-emc-service.de ) with hints to our inventions like GTEM (end of 80s), EUROTEM (End of 90s) etc, plus background (RD-web-section) info. A size limited TEM device can not do everything but may sometimes prove useful. Detailed info also in IEC 61000-20. TEM Devices for radiated emission and immunity.The basic idea is to consider a free space (TEM-basically only mode) wave inside and for emissions use the concept of t o t a l radiated power to correlate to OATS.This requires EUT mechanical rotations in a GTEM (Dr. Perry F. Wilson Algorithm- now working for NIST Bolder Co--He also published an article I think in IEEE EMC Transaction How to correlate below 30 MHz several years ago (mid 90s?) ). At the Apex you receive (based on simple e.g. 3, x-y-z orientation of EUT) voltages vs. frequency to feed into the software correlation algorithm. To be more specific we need to hear details of the product (EUT), in particular size! Cables do also matter! One TEM cell competitor is e.g. compact chambers now. What TEM type of cell are you considering? Regulatory compliance/acceptance under EN 55022/ CISPR 22 issues (accreditation?) may also be an important issue. IEC 61000-20 is just a new basic standard.normative references? The GTEM is listed in the new ANSI/IEEE C 63.4. Diethard Best regards Dr. Diethard Hansen EES President, Principal Consultant, Trainer US Senior NARTE certif. EMC Eng. 001937NE EMC+Automotive+Telecom QM+techn. EA-Auditor Euro EMC SERVICE (EES) Dr.-Ing. D. Hansen POB 64, Bahnhofstr.39, CH-8965 Berikon 2, Switzerland, Swiss VAT (Mwst.)No.:323214 tel./fax: +41 566 33 73 81 German mobile phone: +49(0)1736015909 www.euro-emc-service.de euro.emc.serv...@swissonline.ch ( mailto:diethard.han...@ieee.org) Consulting+Seminars+RD-Projects Marketing+CE-Testing+ww.Audits From: owner-emc-p...@listserv.ieee.org mailto:owner-emc-p...@listserv.ieee.org]On Behalf Of pat_law...@condordc.com Sent: Mittwoch, 17. November 2004 20:19 To: emc-p...@ieee.org Subject: Using TEM cells for radiated emissions at 30MHz Hi: I was given some literature by management recently advertising the use of a TEM cell for radiated emissions: http://www.wavecontrol.com/index2004.php?idioma=2 Our people have the impression that a TEM cell small enough to fit on a table-top could eliminate the need to go to the local OATS. I don't think it's that simple, but I need more solid information. The products I test are component power supplies, using CISPR 22 Class A Class B limits. Most of our emissions are in the range of 30-100MHz. 1) I've heard TEM cells need correlation to an OATS. Is this a one-time correlation (like a calibration), or is it tied to the model being tested? 2) The dimensions of the TEM cell appear small compared to a wavelength at 30MHz. Does the issue of near-field and far-field zones still apply in a TEM cell? If so, how do you correlate the two? 3) The product appears to have pyramid absorbers inside (no reverberation). Does this mean the EUT needs to be repositioned several times during the test? 4) How do the TEM cell correlation factors and noise floor of the spectrum analyzer interact? Do I need a certain maximum noise floor in order to make measurements? I guess I'm looking for a TEM cell tutorial, or maybe a book or paper titled 'TEM Cells For Dummies'. I wrote to the vendor, but they haven't responded. On a slightly different note, has there been any progress for accepting emissions measurements from reverberation chambers (IEC 61000-4-21)? Thanks in advance, Pat Lawler EMC Engineer Condor DC Power Supplies, Inc. --- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri
RE: Using TEM cells for radiated emissions at 30MHz
Pat, I use a TEM cell for some IC measurements and can answer a couple of your questions. My answers are in BLUE below. Dave Cuthbert Micron Technology From: owner-emc-p...@listserv.ieee.org mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of pat_law...@condordc.com Sent: Wednesday, November 17, 2004 12:19 PM To: emc-p...@ieee.org Subject: Using TEM cells for radiated emissions at 30MHz Hi: I was given some literature by management recently advertising the use of a TEM cell for radiated emissions: http://www.wavecontrol.com/index2004.php?idioma=2 Our people have the impression that a TEM cell small enough to fit on a table-top could eliminate the need to go to the local OATS. I don't think it's that simple, but I need more solid information. The products I test are component power supplies, using CISPR 22 Class A Class B limits. Most of our emissions are in the range of 30-100MHz. 1) I've heard TEM cells need correlation to an OATS. Is this a one-time correlation (like a calibration), or is it tied to the model being tested? 2) The dimensions of the TEM cell appear small compared to a wavelength at 30MHz. Does the issue of near-field and far-field zones still apply in a TEM cell? If so, how do you correlate the two? There appears to be no issue with this. I believe the E and H fields assume the impedance ratio of the cell as the energy propagates along the cell. I would like to hear what others say about this. 3) The product appears to have pyramid absorbers inside (no reverberation). Does this mean the EUT needs to be repositioned several times during the test? Yes, unfortunately it must be repositioned in six orientations if you want to cover all possibilities. However, since a DUT is normally placed in one plane only (I.E. on the feet) at an OATS, I suppose the DUT needs only four orientations in a TEM to mimic a DUT being rotated at an OATS. Comments? 4) How do the TEM cell correlation factors and noise floor of the spectrum analyzer interact? Do I need a certain maximum noise floor in order to make measurements? The same as any other SA measurement. At least a 6 dB S/N ratio is needed and preferably 10 dB. I'm looking for a TEM cell tutorial, or maybe a book or paper titled 'TEM Cells For Dummies'. I wrote to the vendor, but they haven't responded. On a slightly different note, has there been any progress for accepting emissions measurements from reverberation chambers (IEC 61000-4-21)? Thanks in advance, Pat Lawler EMC Engineer Condor DC Power Supplies, Inc. --- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Using TEM cells for radiated emissions at 30MHz
Hi: I was given some literature by management recently advertising the use of a TEM cell for radiated emissions: http://www.wavecontrol.com/index2004.php?idioma=2 Our people have the impression that a TEM cell small enough to fit on a table-top could eliminate the need to go to the local OATS. I don't think it's that simple, but I need more solid information. The products I test are component power supplies, using CISPR 22 Class A Class B limits. Most of our emissions are in the range of 30-100MHz. 1) I've heard TEM cells need correlation to an OATS. Is this a one-time correlation (like a calibration), or is it tied to the model being tested? 2) The dimensions of the TEM cell appear small compared to a wavelength at 30MHz. Does the issue of near-field and far-field zones still apply in a TEM cell? If so, how do you correlate the two? 3) The product appears to have pyramid absorbers inside (no reverberation). Does this mean the EUT needs to be repositioned several times during the test? 4) How do the TEM cell correlation factors and noise floor of the spectrum analyzer interact? Do I need a certain maximum noise floor in order to make measurements? I guess I'm looking for a TEM cell tutorial, or maybe a book or paper titled 'TEM Cells For Dummies'. I wrote to the vendor, but they haven't responded. On a slightly different note, has there been any progress for accepting emissions measurements from reverberation chambers (IEC 61000-4-21)? Thanks in advance, Pat Lawler EMC Engineer Condor DC Power Supplies, Inc. --- 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Three-phase mains emissions testing
I agree with Mr. Richards. Not placing the other LISNs in-line would affect the measurement on the LISN that was in-line. From: Bob Richards b...@toprudder.com List-Post: emc-pstc@listserv.ieee.org Date: Fri, 10 Sep 2004 10:49:56 -0700 (PDT) To: emc-p...@ieee.org Subject: Re: Three-phase mains emissions testing Bill, You must have a LISN on all three phases, and neutral if the product has that. All the LISNs not being measured must have the measurement port terminated by a 50 ohm load. You can either use a LISN that has all three phases, or you could use multiple single-conductor LISNs. The measurement method is spelled out in CISPR 22 or 11 or ??, whichever is appropriate for your product. Bob Richards, NCT Square D. Bill Flanigan bflani...@ameritherm.com wrote: Esteemed homologists, Is anyone familiar with the requirements for conducted emissions testing on three-phase mains? Can one impoverished tester insert one rented (30A-capable) LISN to each line in turn, or must the LISN involve all three lines simultaneously? CISPR 16-1 is a little vague on this issue. 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Three-phase mains emissions testing
Bill, You must have a LISN on all three phases, and neutral if the product has that. All the LISNs not being measured must have the measurement port terminated by a 50 ohm load. You can either use a LISN that has all three phases, or you could use multiple single-conductor LISNs. The measurement method is spelled out in CISPR 22 or 11 or ??, whichever is appropriate for your product. Bob Richards, NCT Square D. Bill Flanigan bflani...@ameritherm.com wrote: Esteemed homologists, Is anyone familiar with the requirements for conducted emissions testing on three-phase mains? Can one impoverished tester insert one rented (30A-capable) LISN to each line in turn, or must the LISN involve all three lines simultaneously? CISPR 16-1 is a little vague on this issue. 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Three-phase mains emissions testing
Esteemed homologists, Is anyone familiar with the requirements for conducted emissions testing on three-phase mains? Can one impoverished tester insert one rented (30A-capable) LISN to each line in turn, or must the LISN involve all three lines simultaneously? CISPR 16-1 is a little vague on this issue. Respectfully, WmFlanigan 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
