Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
It's relevant to understand between vertically polarized waves that have a 180 degree phase shift on reflection, and horizontally polarized waves that do not. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens John Woodgate Verzonden: Thursday, December 22, 2011 7:30 PM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: Semi-Anechoic Chamber Question - Correction Factor In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
But the 6dB worst-case correlation should still stand. If a closer estimate is needed, then some numerical analysis is needed, but will always be an approximation. By the way, I understood that a wave reflected (with no energy loss) reflects with 0 phase shift. _ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | Regulatory Compliance Engineering From: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl To: EMC-PSTC@LISTSERV.IEEE.ORG Date: 12/23/2011 02:20 AM Subject: Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor It's relevant to understand between vertically polarized waves that have a 180 degree phase shift on reflection, and horizontally polarized waves that do not. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 �� Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens John Woodgate Verzonden: Thursday, December 22, 2011 7:30 PM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: Semi-Anechoic Chamber Question - Correction Factor In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
And the effect of this phase shift, or no phase shift, would be...??? From: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl To: John Woodgate j...@jmwa.demon.co.uk; EMC-PSTC@LISTSERV.IEEE.ORG Sent: Friday, December 23, 2011 4:58 AM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor It's relevant to understand between vertically polarized waves that have a 180 degree phase shift on reflection, and horizontally polarized waves that do not. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens John Woodgate Verzonden: Thursday, December 22, 2011 7:30 PM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: Semi-Anechoic Chamber Question - Correction Factor In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Constructive vs. destructive interference. Ken Javor Phone: (256) 650-5261 From: Bill Owsley wdows...@yahoo.com Reply-To: Bill Owsley wdows...@yahoo.com Date: Fri, 23 Dec 2011 19:25:13 -0800 (PST) To: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl, John Woodgate j...@jmwa.demon.co.uk, EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: Semi-Anechoic Chamber Question - Correction Factor And the effect of this phase shift, or no phase shift, would be...??? From: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl To: John Woodgate j...@jmwa.demon.co.uk; EMC-PSTC@LISTSERV.IEEE.ORG Sent: Friday, December 23, 2011 4:58 AM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor It's relevant to understand between vertically polarized waves that have a 180 degree phase shift on reflection, and horizontally polarized waves that do not. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl http://www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens John Woodgate Verzonden: Thursday, December 22, 2011 7:30 PM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: Semi-Anechoic Chamber Question - Correction Factor In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk http://www.jmwa.demon.co.uk and www.isce.org.uk http://www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
us in the choir know that. I'm curious about Gerts response since he brought it up twice. I've heard there is more but didn't follow the math for the proof, but the word description made sense. It is interesting in theoretical sense, and in a specific practical experiment to demonstrate it, but not in the practical application with random orientations of various radiators of a EUT. From: Ken Javor ken.ja...@emccompliance.com To: EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Friday, December 23, 2011 10:28 PM Subject: Re: Semi-Anechoic Chamber Question - Correction Factor Re: Semi-Anechoic Chamber Question - Correction Factor Constructive vs. destructive interference. Ken Javor Phone: (256) 650-5261 From: Bill Owsley wdows...@yahoo.com Reply-To: Bill Owsley wdows...@yahoo.com Date: Fri, 23 Dec 2011 19:25:13 -0800 (PST) To: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl, John Woodgate j...@jmwa.demon.co.uk, EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: Semi-Anechoic Chamber Question - Correction Factor And the effect of this phase shift, or no phase shift, would be...??? From: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl To: John Woodgate j...@jmwa.demon.co.uk; EMC-PSTC@LISTSERV.IEEE.ORG Sent: Friday, December 23, 2011 4:58 AM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor It's relevant to understand between vertically polarized waves that have a 180 degree phase shift on reflection, and horizontally polarized waves that do not. Regards, Ing. Gert Gremmen, BSc g.grem...@cetest.nl www.cetest.nl http://www.cetest.nl Kiotoweg 363 3047 BG Rotterdam T 31(0)104152426 F 31(0)104154953 Before printing, think about the environment. -Oorspronkelijk bericht- Van: emc-p...@ieee.org [mailto:emc-p...@ieee.org] Namens John Woodgate Verzonden: Thursday, December 22, 2011 7:30 PM Aan: EMC-PSTC@LISTSERV.IEEE.ORG Onderwerp: Re: Semi-Anechoic Chamber Question - Correction Factor In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk http://www.jmwa.demon.co.uk and www.isce.org.uk http://www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com -
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
This has me bemused; when I was new in the trade, I worked for Wang Labs in Tewksbury, Massachusetts. In fact, I got into the trade there (during the interview i asked to be allowed to play with the receiver -- fun!)... Our chamber was not tall enough to raise antennas to 4 meters; the building was too low; we could only reach 3 meters. So Glen Dash, he of Dash, Strauss and Goodhue, was called in to figure out a work-around. I'm told he said we could not use the chamber! True enough for certification, but we did audits in that chamber, not certification, so I suggested he pick one of our test items as typical, test it in Boxborough at his own site, and then retest it in Tewskbury so we could do exactly as suggested here and apply correction factors. That was done. Basic Physics. We found manufacturing defects. Long leaded transistors oscillating, cabinets modified by a factory to be easier to assemble It must have worked. Which leads to another thing: Most of the really egregious errors aren't 1 or 2 dB; they're 10 or 20. How close does a pretest have to BE? *First define the requirements.* That's basic, too. Cortland RIchmond (KA5S) On 12/22/2011 12:08 AM, Bill Owsley wrote: At a basic level, do an NSA for the chamber and compare to the OATS NSA to develop a correction factor for the two. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Bill, I'd guess 6dB as in voltage, with dBuV being used. Michael Sundstrom OHD / TREQ Dallas Electronic Lab Analyst, EMC Lead 2170 French Settlement Rd, Suite B Dallas, Texas 75212 (214) 579 6312 (940) 390 3644c KB5UKT Albert Einstein once said, The definition of insanity is doing the same thing over and over again and expecting different results. From: Bill Owsley [mailto:wdows...@yahoo.com] Sent: Wednesday, December 21, 2011 11:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor Go back, way back, to the paper by pate, german, smith, on the NSA. Go through all the details and calculations and surmise that there is the direct path, and the reflected path. The reflected path adds, or not, to the direct path, depending on wavelength (phase at receive antenna) and distance between antennas. A scan up to 4 meters will generally cover the apparent phase shift at the lower frequencies such that a maximum is recorded. This scan will certainly cover the apparent phase shift of higher freq's. The reflected wave verses the direct wave, will have a longer distance and thus a little more loss. In the worst case, it can be neglected. It will also suffer some loss at the reflecting surface, generally assumed to be a perfect boundary since it is unknown but defined as metal. Thus, the received voltage received via a direct path added with a reflected path, assuming no distance or reflection loss, would be 6 dB higher than the direct path alone. This direct path alone is the assumed field measured in a FAC, neglecting any chamber anomalies. Or is it 3 dB higher?? as in power? From: Grasso, Charles charles.gra...@echostar.com To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, December 21, 2011 4:29 PM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.commailto:3032042...@vtext.com (e) charles.gra...@echostar.commailto:charles.gra...@echostar.com (e2) chasgra...@gmail.commailto:chasgra...@gmail.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
In message 1324530145.50231.yahoomail...@web39603.mail.mud.yahoo.com, dated Wed, 21 Dec 2011, Bill Owsley wdows...@yahoo.com writes: Thus, the received voltage received via a direct path added with a reflected path, assuming no distance or reflection loss, would be 6 dB higher than the direct path alone. This direct path alone is the assumed field measured in a FAC, neglecting any chamber anomalies. Or is it 3 dB higher?? as in power? If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Voltage or power, a dB is a dB. Constructive interference between the direct and reflected ray (given a perfectly conductive ground plane) can increase the field intensity by a factor of two if the phase difference between the two is a half-wavelength. That is 6 dB, whether you speak of the field intensity, or the signal power at the antenna port measured at the EMI receiver. Ken Javor Phone: (256) 650-5261 From: Sundstrom, Michael michael_sundst...@overheaddoor.com Date: Thu, 22 Dec 2011 07:54:21 -0600 To: Bill Owsley wdows...@yahoo.com, EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Conversation: [PSES] Semi-Anechoic Chamber Question - Correction Factor Subject: RE: [PSES] Semi-Anechoic Chamber Question - Correction Factor Bill, I¹d guess 6dB as in voltage, with dBuV being used. Michael Sundstrom OHD / TREQ Dallas Electronic Lab Analyst, EMC Lead 2170 French Settlement Rd, Suite B Dallas, Texas 75212 (214) 579 6312 (940) 390 3644c KB5UKT Albert Einstein once said, The definition of insanity is doing the same thing over and over again and expecting different results. From: Bill Owsley [mailto:wdows...@yahoo.com] Sent: Wednesday, December 21, 2011 11:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor Go back, way back, to the paper by pate, german, smith, on the NSA. Go through all the details and calculations and surmise that there is the direct path, and the reflected path. The reflected path adds, or not, to the direct path, depending on wavelength (phase at receive antenna) and distance between antennas. A scan up to 4 meters will generally cover the apparent phase shift at the lower frequencies such that a maximum is recorded. This scan will certainly cover the apparent phase shift of higher freq's. The reflected wave verses the direct wave, will have a longer distance and thus a little more loss. In the worst case, it can be neglected. It will also suffer some loss at the reflecting surface, generally assumed to be a perfect boundary since it is unknown but defined as metal. Thus, the received voltage received via a direct path added with a reflected path, assuming no distance or reflection loss, would be 6 dB higher than the direct path alone. This direct path alone is the assumed field measured in a FAC, neglecting any chamber anomalies. Or is it 3 dB higher?? as in power? From: Grasso, Charles charles.gra...@echostar.com To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, December 21, 2011 4:29 PM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com mailto:3032042...@vtext.com (e) charles.gra...@echostar.com mailto:charles.gra...@echostar.com (e2) chasgra...@gmail.com mailto:chasgra...@gmail.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
There is a theoritical NSA program on the ETS website that will calculate the NSA for any given distance and scan height. I used it to generate numbers for a compliant 3m site (1 to 4m recieve scan height) and then ran the numbers with the transmit and recieve antenna heights at something like 30 meters. The difference was a nominal 6dB. Bob R. --- On Thu, 12/22/11, Sundstrom, Michael michael_sundst...@overheaddoor.com wrote: From: Sundstrom, Michael michael_sundst...@overheaddoor.com Subject: RE: [PSES] Semi-Anechoic Chamber Question - Correction Factor To: Bill Owsley wdows...@yahoo.com, EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Date: Thursday, December 22, 2011, 8:54 AM Bill, I’d guess 6dB as in voltage, with dBuV being used. Michael Sundstrom OHD / TREQ Dallas Electronic Lab Analyst, EMC Lead 2170 French Settlement Rd, Suite B Dallas, Texas 75212 (214) 579 6312 (940) 390 3644c KB5UKT Albert Einstein once said, The definition of insanity is doing the same thing over and over again and expecting different results. From: Bill Owsley [mailto:wdows...@yahoo.com] Sent: Wednesday, December 21, 2011 11:02 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor Go back, way back, to the paper by pate, german, smith, on the NSA. Go through all the details and calculations and surmise that there is the direct path, and the reflected path. The reflected path adds, or not, to the direct path, depending on wavelength (phase at receive antenna) and distance between antennas. A scan up to 4 meters will generally cover the apparent phase shift at the lower frequencies such that a maximum is recorded. This scan will certainly cover the apparent phase shift of higher freq's. The reflected wave verses the direct wave, will have a longer distance and thus a little more loss. In the worst case, it can be neglected. It will also suffer some loss at the reflecting surface, generally assumed to be a perfect boundary since it is unknown but defined as metal. Thus, the received voltage received via a direct path added with a reflected path, assuming no distance or reflection loss, would be 6 dB higher than the direct path alone. This direct path alone is the assumed field measured in a FAC, neglecting any chamber anomalies. Or is it 3 dB higher?? as in power? From: Grasso, Charles charles.gra...@echostar.com To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, December 21, 2011 4:29 PM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long and the lowest frequency where a null can occur is where the difference in path length is 180 degrees. That's at 250 MHz, but the reflected signal being subject to the inverse square law can't completely cancel the direct ray, only reduce it. and cna't increase it by the full 6 dB. I've played around in an old style TEMPEST test chamber with no cones or tiles and seen 30 dB+ cancellation between two Bicons, but that is from multiple reflections. 10 meter OATS are closer. Have used one for GR 0189. In Winter. In Collin County, Texas. Had to chip ice off the gate to get in. B! Cortland KA5S - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011, Cortland Richmond k...@earthlink.net writes: On 12/22/2011 9:27 AM, John Woodgate wrote: If the direct and reflected rays are equal amplitude and in phase, then it's +6 dB; if they are at 180 degrees, it's minus infinity dB. In between you can get any value, depending on relative phase and transmission loss. Equal amplitude only occurs if the direct and reflected paths are the same distance. A 3 meter OATS can never meet that condition. If the source and antenna are at 1 meter height, the reflected path is 3.6 meters long My explanation, including 'If', was in the context of doubt between 3 dB and 6 dB. Your further information is relevant, but doesn't invalidate what I wrote. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK Some people who are peeling the finch of the financial crisis are thinking of biting a rook. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.commailto:3032042...@vtext.com (e) charles.gra...@echostar.commailto:charles.gra...@echostar.com (e2) chasgra...@gmail.commailto:chasgra...@gmail.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.orgmailto:emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.netmailto:emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.orgmailto:mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.orgmailto:j.bac...@ieee.org David Heald dhe...@gmail.commailto:dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Go back, way back, to the paper by pate, german, smith, on the NSA. Go through all the details and calculations and surmise that there is the direct path, and the reflected path. The reflected path adds, or not, to the direct path, depending on wavelength (phase at receive antenna) and distance between antennas. A scan up to 4 meters will generally cover the apparent phase shift at the lower frequencies such that a maximum is recorded. This scan will certainly cover the apparent phase shift of higher freq's. The reflected wave verses the direct wave, will have a longer distance and thus a little more loss. In the worst case, it can be neglected. It will also suffer some loss at the reflecting surface, generally assumed to be a perfect boundary since it is unknown but defined as metal. Thus, the received voltage received via a direct path added with a reflected path, assuming no distance or reflection loss, would be 6 dB higher than the direct path alone. This direct path alone is the assumed field measured in a FAC, neglecting any chamber anomalies. Or is it 3 dB higher?? as in power? From: Grasso, Charles charles.gra...@echostar.com To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, December 21, 2011 4:29 PM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com From:emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
At a basic level, do an NSA for the chamber and compare to the OATS NSA to develop a correction factor for the two. From: Grasso, Charles charles.gra...@echostar.com To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, December 21, 2011 4:29 PM Subject: RE: Semi-Anechoic Chamber Question - Correction Factor Professor Leferink published a nice paper that proposed a different correction factor for a SAC to a FAC. I tried to track it down but had no luck. Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com From:emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Jim Hulbert Sent: Monday, December 19, 2011 2:27 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: Semi-Anechoic Chamber Question Thank you everyone for the helpful feedback. The consensus is clearly: Save my back and leave the absorber and ferrite tiles in place. Compare radiated emissions measurements in the chamber to those on the OATS (several suggested a comb generator for this purpose). Assign an adjustment factor to the chamber measurements to correlate as closely as possible to the OATS measurements (6dB has been suggested as a reasonable factor, although I need to confirm this through my own measurements). Jim - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://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...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
