RE: FCC Immunity Requirements
A good EMC engineer makes it pass without changing anything. A great EMC engineer makes it pass by deleting a part or two and taking credit for the cost reduction. From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Pettit, Ghery Sent: Friday, May 02, 2008 12:14 PM To: John Woodgate; Richards, Carl Cc: Ken Javor; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: FCC Immunity Requirements No, the EMC and safety guys are told to make it pass, but don't change anything. :-) From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of John Woodgate Sent: Friday, May 02, 2008 9:08 AM To: Richards, Carl Cc: Ken Javor; EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: FCC Immunity Requirements In message e1e443d9fa97c74d8cd610a12f276e6095d...@asp1exch2.aspect.com, dated Fri, 2 May 2008, Richards, Carl carl.richa...@aspect.com writes: only the very poorest newcomer (poorest in the sense of piss poor planning) would embark upon the design of a product and then discover that it?s product failed to meet the regs during the testing phase. Pardon? This is standard industry practice. It shouldn't be, but it is. The design is 'finished' and THEN the safety and EMC experts get to re-design it for compliance at huge cost and very damaging delay. Only a few enlightened companies build in safety and EMC from Day 1 of the design phase. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Murphy's Law has now been officially re-named The Certainty Principle 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 - 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: earthline choke
In the computer world of switch mode power supplies this choke is usually used as a means to control common mode radiation from the 1.5-2 meter line cord in the 30-100 MHz range. Typically consisting of a ferrite (850mu) with several turns of the green/yellow safety ground through it. If a real inductor were used here then it would be required to meet a minimum resistance to keep from being a safety issue. This configuration may have an effect on the higher frequencies in line conducted measurements but most conducted emissions are controlled by the X and Y caps along with the CM choke on the line and neutral in the AC input. Earl From: Muriel Bittencourt de Liz [mailto:mur...@eel.ufsc.br] Sent: Thursday, September 11, 2003 8:41 AM To: Ken Javor; Paolo Peruzzi; emc-p...@majordomo.ieee.org Subject: Re: earthline choke I have got some good results using a choke in the safety ground (or protective earth-PE, as you wish) for reducing conducted emissions in switched mode power supplies. I also remember that I read somewhere (i think it was Clayton Paul's book) that the use of this choke on safety wire is a problem for conformity with the safety standards, so its use it is not recommended from this viewpoint. I'd like to know if someone could give some additional details about using this kind of solution for reducing conducted EMI, and if it is possible to use it or not, depending on the safety standards. Another issue would be: what is the effect of using this solution in terms of radiated emissions?? They are increased or not?? Thanks in advance, and best regards, Muriel - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: Paolo Peruzzi paolo.peru...@esaote.com; emc-p...@majordomo.ieee.org Sent: Thursday, September 11, 2003 9:11 AM Subject: Re: earthline choke A choke in the safety ground could replace a common mode choke in the mains lines, but only if the enclosure of the filtered device is isolated from trolley structure completely, and the capacitance between equipment enclosure and trolley structure is controlled to provide a higher impedance than through the filtered safety ground wire (over the frequency range of interest). If there is a short and the ground wire performs its function the choke will saturate and become ineffective but that is a moot point under short circuit conditions. During the time it takes the choke to saturate it will buck the increase in current and keep the shorting potential on the equipment enclosure; I expect this will be on the order of a millisecond or less and shouldn't be a safety issue, but there are lots of product safety people on the list who can weigh in on that subject more authoritatively than I do. on 9/11/03 4:03 AM, Paolo Peruzzi at paolo.peru...@esaote.com wrote: Dear all, I'm involved in the design of a mains filter of a trolley and I'm discussing with my colleagues about the convenience of inserting an inductance on the protective earth conductor. I'm quite sceptical regarding EMC advantages of such a solution, but I haven't much experience on that. Have you any hints on the subject? best regards, Paolo Peruzzi ** Paolo Peruzzi Esaote S.p.A. Research Product Development - Design Quality Control via di Caciolle, 15 I- 50127 Florence tel: +39 055 4229469 fax: +39 055 4223305 e-mail: paolo.peru...@esaote.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc 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 Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc 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 Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and
RE: cable maximization - do you or don't you??
When the standards changed to move the EUT and peripherals to the back edge of the test table, cable maximization was left mostly up to gravity with the cables being draped as they fell. Most test facilities do not go any further than that. I have seen OEMs that go so far as to do cable MINimization. Tune it to pass. They aren't doing anybody a favor. I would continue to insist on maximization of both cable and peripherals especially in development testing when early identification of a potential problem could save you lots of headache later on. Earl From: Charles Grasso [mailto:cgrassospri...@earthlink.net] Sent: Sunday, July 06, 2003 4:54 PM To: Emc-Pstc; charles.gra...@echostar.com Subject: cable maximization - do you or don't you?? Hi all, I have recently run into an issue with an OEM supplier. The product that we are looking at fails emissions after cable maximization. In an informal study, I discovered that quite a few labs don't seem to perform cable maximization on a routine basis. ANSIC63 is quite clear on this - the cables need to be maximized. Is cable maximization a thing of the past - to be written out - and test labs are maximizing throughput rather than cables OR is is something I should continue to insist on?? Comments will be gratefully accepted. Charles Grasso EchoStar Communicationa This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc 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 Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc 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 Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: OK, what's going on?
Amen! I had 15 years of computer EMC when I left the PC sector this year. This was a never ending source of frustration. I won't even get into the shortcomings of the measurement standards. The emigration of PC manufacturing to the PAC rim is being followed by emigration of the design and validation teams also. Many PC manufacturers have completely outsourced their EMC testing to the OEM PC manufacturers even when they own several 10 meter semi anechoic chambers. This is akin to having the fox watch over the hen house. Management says it is more economical that way. When every test is compliant and product passes the first time every time then I guess it is. Besides, it isn't compliance that anyone is really after anymore but rather a piece of paper that says it is compliant. (Neville Chamberlain effect) Maybe it doesn't matter anyway. Most customers don't care if it meets EMC requirements. Most only relate features to price and EMC is not a feature they would pay for. An EMC engineer can't tell whether a PC passes or fails without an expensive test site chock full of equipment so how is a consumer supposed to tell? A few commercial and government customers perform audit tests before entering into contracts but most don't seem to care. I seem to remember an FCC employee speaking at a conference somewhere stating that they don't get computer interference complaints. Mostly telephone interference complaints but never computer interference. Most of the field complaints I worked on were immunity related. Customers care and complain about that. In today's computer industry the companies that aggressively pursue EMC are penalized by adding more cost while the companies that ignore it are able to produce a more inexpensive product. The vigilant companies will not be able to compete. I agree, enforce the emissions standards or drop them. Earl Morse ex-Major PC Company EMC guru -Original Message- From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Tuesday, March 25, 2003 7:38 PM To: 'lfresea...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: OK, what's going on? Hi Derek - Go Reds!! This is not a surprise to me. I have railed at much length a couple of years ago as to the latest FCC changes to the emissions qualification. I am sure you are familiar with it so I won't belabour the point. Fundementally the FCC PC emissions procedure has rendered the EMC discipline almost irrelevent. The new procedures coupled with the lack of enfocement makes it difficult to justify the increased costs of EMC design test. It also makes the whole measurement uncertainty push ridiculous. After all if the procedures allow for prodcut that 20dB out of spec why bother with a couple of dB of error?? Lets give the emissions standards some teeth or eliminate it all together. 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: lfresea...@aol.com [mailto:lfresea...@aol.com] Sent: Tuesday, March 25, 2003 1:05 PM To: emc-p...@majordomo.ieee.org Subject: OK, what's going on? Hi all, This e-mail has been prompted because of a number of things that have all come together. This may take a little reading, but please stick with it. Last note... this is not intended to pick on any individuals, or organization, but I do want to stir the pot. I operate an engineering lab, helping clients harden their designs to meet EMC requirements. In this particular instance, I was working for a small client, on a card that goes in the PC . In order to test I need a host PC. So, to save money, the card maker supplies 2 clones. Neither of the two PCs passed emissions testing with the card, in fact, above 100 MHz, they fail even the Class A limit: badly! So, before calling my client, I pull his card, the PC is no different, I pull the monitor, then the keyboard, then the mouse... No different. I test just the PC chassis one at a time. On their own, booted and then the peripherals removed. Not even close to passing. Disgruntled, I get my office PC... Fail. I get my kids PC.. over 20 dB over the limit! So, I think so much for clones... I buy 2 Dell ( sorry, no point trying to hide names... ) desktops, both fail, quite badly. However, they have very similar noise profiles... Can 5 PC's all fail? I think my measuring system is set -up wrong. So I verify this. I am within 1 dB of what I expect when I inject a signal from a signal generator and account for antenna factors. Here lies the question: why can I not find a PC that passes? Worse, since they don't pass, who is chasing them down to enforce the requirements? I'm unhappy, because I am taking a clients money to make him meet the requirements, when it seems no one else is. Now, what's making this worse for me, is that
RE: OK, what's going on?
Most of the stuff I worked on was global. The same box went everywhere with the appropriate language pack installed. There are some companies that are NA sales only and we did have a few consumer products that were marketed that way. From: Stone, Richard A (Richard) [mailto:rsto...@lucent.com] Sent: Wednesday, March 26, 2003 11:44 AM To: 'Morse, Earl (E.A.)'; 'Grasso, Charles'; 'lfresea...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: OK, what's going on? thats true Earl, good point on company B, not caring but selling with a higher profit, less EMC..company A busting butt to pass and comply with integrity. as for immunity... do any PC makers manufacturer any PC's strictly for sales in USA...only need Emissions here. that would save 1000's in emc costs, never mind engineering to fix the problems.. of course you would need diff. p/n's then. and sales,manuals, compliance certs..etc would be altered. has anyone ever done a cost estimate based on building a USA vs. EU chassis? curious to see if its worth the time. From: Morse, Earl (E.A.) [mailto:emo...@ford.com] Sent: Wednesday, March 26, 2003 11:10 AM To: 'Grasso, Charles'; 'lfresea...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: OK, what's going on? Amen! I had 15 years of computer EMC when I left the PC sector this year. This was a never ending source of frustration. I won't even get into the shortcomings of the measurement standards. The emigration of PC manufacturing to the PAC rim is being followed by emigration of the design and validation teams also. Many PC manufacturers have completely outsourced their EMC testing to the OEM PC manufacturers even when they own several 10 meter semi anechoic chambers. This is akin to having the fox watch over the hen house. Management says it is more economical that way. When every test is compliant and product passes the first time every time then I guess it is. Besides, it isn't compliance that anyone is really after anymore but rather a piece of paper that says it is compliant. (Neville Chamberlain effect) Maybe it doesn't matter anyway. Most customers don't care if it meets EMC requirements. Most only relate features to price and EMC is not a feature they would pay for. An EMC engineer can't tell whether a PC passes or fails without an expensive test site chock full of equipment so how is a consumer supposed to tell? A few commercial and government customers perform audit tests before entering into contracts but most don't seem to care. I seem to remember an FCC employee speaking at a conference somewhere stating that they don't get computer interference complaints. Mostly telephone interference complaints but never computer interference. Most of the field complaints I worked on were immunity related. Customers care and complain about that. In today's computer industry the companies that aggressively pursue EMC are penalized by adding more cost while the companies that ignore it are able to produce a more inexpensive product. The vigilant companies will not be able to compete. I agree, enforce the emissions standards or drop them. Earl Morse ex-Major PC Company EMC guru -Original Message- From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Tuesday, March 25, 2003 7:38 PM To: 'lfresea...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: OK, what's going on? Hi Derek - Go Reds!! This is not a surprise to me. I have railed at much length a couple of years ago as to the latest FCC changes to the emissions qualification. I am sure you are familiar with it so I won't belabour the point. Fundementally the FCC PC emissions procedure has rendered the EMC discipline almost irrelevent. The new procedures coupled with the lack of enfocement makes it difficult to justify the increased costs of EMC design test. It also makes the whole measurement uncertainty push ridiculous. After all if the procedures allow for prodcut that 20dB out of spec why bother with a couple of dB of error?? Lets give the emissions standards some teeth or eliminate it all together. 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: lfresea...@aol.com [mailto:lfresea...@aol.com] Sent: Tuesday, March 25, 2003 1:05 PM To: emc-p...@majordomo.ieee.org Subject: OK, what's going on? Hi all, This e-mail has been prompted because of a number of things that have all come together. This may take a little reading, but please stick with it. Last note... this is not intended to pick on any individuals, or organization, but I do want to stir the pot. I operate an engineering lab, helping clients harden their designs to meet EMC requirements. In this particular instance, I was working for a small client, on a card that goes in the PC
RE: ESD - time between successive discharges
Our rule is 1 second per discharge, 10 discharges, both polarities, per discharge point. Of course the test personnel also strafe the unit at 20 pulses/second in order to detect any vulnerability that may need to be exploited. -Original Message- From: Cortland Richmond [mailto:72146@compuserve.com] Sent: Saturday, August 04, 2001 8:40 PM To: ieee pstc list Subject: Re: ESD - time between successive discharges This has come up everywhere I've worked. In order to adequately test for vulnerability, logically, one has to apply a discharge during each of the operating conditions an equipment might take. Given the number of different logical states a microprocessor-controlled EUT might use, this could take forever! From the standpoint of doing a conscientious test, it would be desirable to test MORE often than once per second. But because the real-world ESD event is an isolated one, repeated discharges are not a realistic test. Also, many devices incorporate built-in ESD protection using protective parts of limited dissipation, and it is possible testing TOO often will destroy the protection circuit. Once per second turns out to be a compromise, and one which may be followed without being too persnickety. What about a longer interval? Sure -- provided we test all of the logic states that might be latched up by the discharge! Ten discharges per point, plus and minus, at each of the voltage levels prescribed, will probably turn up enough of them to pin down a susceptible device no matter WHAT the interval is. One hour? Well, if you can afford to do thirty hours of test, you can do three points at ONE voltage level. One minute? Still takes a long time. And let's face it; this is mind-numbing work. So one second seems to ME to be just about right. Let the poor tech -- or the poor engineer! -- take a break once in a while! I'll add that there may be failure modes that take longer than one second to show up. You want to do the test in such a way that the tester can note and adjust to this; I once tested something that had a 30 second delay before a failure showed up. This can't be helped, and, in this particular case, one second is far too often. Cortland Richmond --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.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.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.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.rcic.com/ click on Virtual Conference Hall,
RE: EMC Circuit Board Design
The number one problem with PCB board routing that we encounter that can be attributed to the layout personnel is: Routing high speed signal traces without regard for return current paths. Either the signals are routed across splits in the reference plane or the signal switches layers and the new reference plane doesn't have a good path to the old plane. Both problems result in higher emissions and poor signal integrity. Earl Morse Portable Division EMC Design Compaq Computer Corporation Phone: 281.927.3607 Pager: 713.717.0824 Fax: 281.927.3654 Email: earl.mo...@compaq.com mailto:earl.mo...@compaq.com Emissions Control Laboratory 10320 Rodgers Road, EC106 Houston, TX 77070 -Original Message- From: rehel...@mmm.com [mailto:rehel...@mmm.com] Sent: Friday, January 21, 2000 6:48 AM To: emc-p...@majordomo.ieee.org Subject:EMC Circuit Board Design Dear List-Members, I am requesting information/opinions/etc. on the following: When circuit boards are designed, what are the common mistakes that the circuit board designers make regarding EMC (multi-layer boards in particular)? You can respond to me directly but I would prefer a response to the list as I believe that the question is of interest to many on this list-server. In either event I will compile the responses and resend the compilation later. Thanks for your time, Bob Heller 3M Company - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
EN61000-4-11
When testing a device like a notebook computer that incorporates a battery should the battery be removed for this test? If the battery is installed any event will have to exceed the life of the battery in order to affect the system performance. A built in UPS so to speak. Earl Morse Portable Division EMC Design Compaq Computer Corporation Phone: 281.927.3607 Pager: 713.717.0824 Fax: 281.927.3654 Email: earl.mo...@compaq.com mailto:earl.mo...@compaq.com Emissions Control Laboratory 10320 Rodgers Road, EC106 Houston, TX 77070 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: NEAR/ FAR FIELD CORRELATION ISSUES
I beg to differ. It is ludicrous to believe that components or for that matter subassemblies can be certified and then combined to make a compliant system. CE + CE doesn't always equal CE The reduction of emissions is highly reliant on component placement. The same parts can be arranged on circuit boards in compliant and non-compliant patterns. Same with subassemblies. While the current measurement techniques are difficult they are about as close to the truth as we can get. Even if that means an 8 dB swing from site to site. The reason that we see PCs consistently fail by as much as 20 dB is because of a lack of enforcement. Many computer manufacturers sneak through the requirements with their one of a kind golden units never to worry about compliance again. Very few get caught and it is worth the bucks to keep the production lines going rather than shutdown the lines. Who was the last computer manufacturer you heard of that was forced to shutdown until an EMC problem was fixed? I have a book of test reports on competitor's products. They fall into the categories of compliant, near compliant (looks like they tried), and fails miserably (didn't try, didn't care, and outright lied on any self declarations). The failing companies seem to be doing just as brisk a business as the passing companies without having to worry about the cost of EMC. Earl Morse Portable Division EMC Design Compaq Computer Corporation Phone: 281.927.3607 Pager: 713.717.0824 Fax: 281.927.3654 Email: earl.mo...@compaq.com mailto:earl.mo...@compaq.com -Original Message- From: Grasso, Charles (Chaz) [mailto:gra...@louisville.stortek.com] Sent: Friday, June 18, 1999 10:33 AM To: 'Lou Gnecco'; emc-p...@majordomo.ieee.org Subject:RE: NEAR/ FAR FIELD CORRELATION ISSUES I cannot agree more!! We, not the government, need to drive the technology for EMC. I have followed this thread with interest. I have long believed that if EMC was to maintain credibility we (EMC ) would have to come up with a method of demonstrating compliance in spite of the many and varied combinations. One way is to test at the component level - like our Safety brethren - and call the assembly of tested components good!! This is methodology can be made consistent with good engineering design practice unlike the existing FCC rules for Class B equipment. On the surface the FCC Rules appear to be similar to component level testing - but under the hood, they are completely different. There are PCs out there that fail by as much as 20dB. I am all for a more logical and consistent design approach to EMC!! Thank you Charles Grasso Advisory Engineer StorageTek 2270Sth 88th Street Louisville CO 80027 M/S 4247. Tel:303-673-2908 Fax:303-661-7115 email:gra...@louisville.stortek.com Web Site: http://www.ewh.ieee.org/r5/denver/rockymountainemc/ -Original Message- From: Lou Gnecco [mailto:l...@tempest-inc.com] Sent: Friday, June 18, 1999 6:52 AM To: emc-p...@majordomo.ieee.org Subject: Re: NEAR/ FAR FIELD CORRELATION ISSUES For this to work, the government would have to change the rules completely, setting a new set of near field procedures and limits. This is doable but hard to sell. A good way to start would be if we did it. If someone in industry writes up a procedure and a set of limits, then everyone could use that as a straw man, (criticizing and refining it) until eventually most people agreed. Eventually it could become an industrial (such as IEEE) standard. Then the govt would find it much easier to adopt it as is or after making their own modifications. lou - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org
