Re: R: R: Conducted Emissions on Telecom Ports
The point is that RE/CE protect broadcast bands. Making an RE measurement (E or H field, regardless) from a LAN line a couple meters long is not representative of what you would measure if the LAN line were significantly longer, as it might be in situ. Therefore a CE measurement can be better correlated to predicted RE from a much longer line (at frequencies where the tested LAN line is electrically short. -- From: Paolo Roncone paolo.ronc...@compuprint.it To: 'Ken Javor' ken.ja...@emccompliance.com, 'Cortland Richmond' 72146@compuserve.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: R: R: Conducted Emissions on Telecom Ports Date: Fri, Sep 8, 2000, 3:51 AM Ken and Cortland and many others that entered this subject : First, radiated emissions are best measured with radiated (not conducted) measurements. There is a correlation between CM currents and RE but that's not all (resonances, cable layout etc. count a lot). Second, you say that CE are easier to measure than RE ? Agree if you talk about emissions on AC power cords (as per CISPR22 and FCC part 15). But for the new requirements on telecom ports, I suggest you to take a look at the new (3.ed.) CISPR22 or EN55022 (sec. 9.5 + annex C.1) and may be you change your opinion ! Radiated emissions above 30 MHz are already covered. If you wanna take care of lower frequencies ( 30 MHz) take a loop antenna (remember the old VDE rules ?) and measure radiated H-fields with your system in the same (typical) layout used for the higher frequencies (with whatever cables you specify, UTS, STP etc.). I am sure that is much quicker, easier and repeatable than all the nonsense (ISNs, CDNs, clamps, current probes, capacitive probes, ferrites, 150 ohm resistors, signal generators, impedance measurements, voltage measurements, current measurements and more) in the new CISPR22. As for the question of outside world, I think in this ever more connected world the border line between INSIDE and OUTSIDE is getting more and more blurred, BUT I also think that a line must be drawn by the standard bodies, otherwise it's gonna really get too much confusing (hope some CISPR/CENELEC member gets it). If we spill over the line (office, floor, building... whatever), emissions requirements are triggered. But within that line it's to be considered an intra-system (what's the system ? that's another good question to be settled) interference potential and the manufacturer should take care of it without need of enforcement because he has all the interest in making a product (system) that works properly and reliably. One last point: based on David Sterner's note, looks to me that North America has a pretty extensive Ethernet and-the-like network. I honestly don't know if the FCC has already enforced emission limits on LAN ports. Anyway, based on David's note looks like there are no complaits of interference with TV and telephones. And please note, this is the very bottom line of it. Emission limits should be intended to protect public services ... and physics works the same on both sides of the Atlantic... or not My personal opinion ... Paolo -Messaggio originale- Da: Ken Javor [SMTP:ken.ja...@emccompliance.com] Inviato: giovedì 7 settembre 2000 18.43 A: Paolo Roncone; 'eric.lif...@ni.com' Cc: 'emc-p...@ieee.org' Oggetto: Re: R: Conducted Emissions on Telecom Ports Although I don't work commercial EMC on a regular basis and I do not know over what frequency range the telecom port CE are controlled (I assume here 150 kHz - 30 MHz), I believe that there is a mistaken premise inherent in the comments to which I am responding. The purpose of controlling common mode CE on any port is not to protect equipment at the other end of the cable, or other co-sited cables, but rather to control radiated emissions in a frequency range in which CE are easier to measure than RE. In turn, the purpose of controlling RE is to protect broadcast radio reception. -- From: Paolo Roncone paolo.ronc...@compuprint.it To: 'eric.lif...@ni.com' eric.lif...@ni.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: R: Conducted Emissions on Telecom Ports Date: Thu, Sep 7, 2000, 9:45 AM Hi Eric, I 100% agree with you. The scope of emissions standard should be to protect the outside (i.e. public) environment from interference. So only ports that connect to public telecom networks should be covered by the standard. The problem is (as pointed out in one of the previous notes) that the new CISPR22 / EN55022 standard clearly includes LAN ports in the definition of telecommunications ports (section 3.6) no matter if they connect to the outside world or not. Regards, Paolo Roncone Compuprint s.p.a. Italy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to:
RE: R: Conducted Emissions on Telecom Ports
Paolo, Physics does work the same on both side of the Atlantic, but human rationale does not necessarily! Tania Grant, tgr...@lucent.com Lucent Technologies, Switching Solutions Group Intelligent Network and Messaging Solutions -- From: Paolo Roncone[SMTP:paolo.ronc...@compuprint.it] Reply To: Paolo Roncone Sent: Friday, September 08, 2000 3:51 AM To: 'Ken Javor'; 'Cortland Richmond' Cc: 'emc-p...@ieee.org' Subject: R: R: Conducted Emissions on Telecom Ports Ken and Cortland and many others that entered this subject : First, radiated emissions are best measured with radiated (not conducted) measurements. There is a correlation between CM currents and RE but that's not all (resonances, cable layout etc. count a lot). Second, you say that CE are easier to measure than RE ? Agree if you talk about emissions on AC power cords (as per CISPR22 and FCC part 15). But for the new requirements on telecom ports, I suggest you to take a look at the new (3.ed.) CISPR22 or EN55022 (sec. 9.5 + annex C.1) and may be you change your opinion ! Radiated emissions above 30 MHz are already covered. If you wanna take care of lower frequencies ( 30 MHz) take a loop antenna (remember the old VDE rules ?) and measure radiated H-fields with your system in the same (typical) layout used for the higher frequencies (with whatever cables you specify, UTS, STP etc.). I am sure that is much quicker, easier and repeatable than all the nonsense (ISNs, CDNs, clamps, current probes, capacitive probes, ferrites, 150 ohm resistors, signal generators, impedance measurements, voltage measurements, current measurements and more) in the new CISPR22. As for the question of outside world, I think in this ever more connected world the border line between INSIDE and OUTSIDE is getting more and more blurred, BUT I also think that a line must be drawn by the standard bodies, otherwise it's gonna really get too much confusing (hope some CISPR/CENELEC member gets it). If we spill over the line (office, floor, building... whatever), emissions requirements are triggered. But within that line it's to be considered an intra-system (what's the system ? that's another good question to be settled) interference potential and the manufacturer should take care of it without need of enforcement because he has all the interest in making a product (system) that works properly and reliably. One last point: based on David Sterner's note, looks to me that North America has a pretty extensive Ethernet and-the-like network. I honestly don't know if the FCC has already enforced emission limits on LAN ports. Anyway, based on David's note looks like there are no complaits of interference with TV and telephones. And please note, this is the very bottom line of it. Emission limits should be intended to protect public services ... and physics works the same on both sides of the Atlantic... or not My personal opinion ... Paolo -Messaggio originale- Da: Ken Javor [SMTP:ken.ja...@emccompliance.com] Inviato: giovedì 7 settembre 2000 18.43 A:Paolo Roncone; 'eric.lif...@ni.com' Cc: 'emc-p...@ieee.org' Oggetto: Re: R: Conducted Emissions on Telecom Ports Although I don't work commercial EMC on a regular basis and I do not know over what frequency range the telecom port CE are controlled (I assume here 150 kHz - 30 MHz), I believe that there is a mistaken premise inherent in the comments to which I am responding. The purpose of controlling common mode CE on any port is not to protect equipment at the other end of the cable, or other co-sited cables, but rather to control radiated emissions in a frequency range in which CE are easier to measure than RE. In turn, the purpose of controlling RE is to protect broadcast radio reception. -- From: Paolo Roncone paolo.ronc...@compuprint.it To: 'eric.lif...@ni.com' eric.lif...@ni.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: R: Conducted Emissions on Telecom Ports Date: Thu, Sep 7, 2000, 9:45 AM Hi Eric, I 100% agree with you. The scope of emissions standard should be to protect the outside (i.e. public) environment from interference. So only ports that connect to public telecom networks should be covered by the standard. The problem is (as pointed out in one of the previous notes) that the new CISPR22 / EN55022 standard clearly includes LAN ports in the definition of telecommunications ports (section 3.6) no matter if they connect to the outside world or not. Regards, Paolo Roncone Compuprint s.p.a. Italy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list
RE: HALT/HASS Testing
HALT. Highly Accelerated Stress Testing. This can go by other names. This is where you stress the product (prototype stage typically) using a number of criteria, the most common being temperature extremes and vibration. You test first to determine the operational limits of the EUT (fails to operate but recovers when the stresses are removed), then continue until you reach the destruct limits (unit is damaged). The test is of short duration (couple days) and is intended to simulate life expectancy. This can be shown using mathematical analysis with the Arrhenius equation among others. There has also been a high degree of correlation experimentally. The failures seen in HALT are usually what you see in the field. The idea is to find the weak points in your product, remedy them, such as using a higher rated part, then re-test to find the new limits. The goal is to add lots of margin concerning the reliability of your product. These tests must be done in specially designed chambers (called HALT chambers by most). They start around $130K. If you don't have the money to buy one there several labs that will gladly do the tests. One such lab is Qualmark. Others are popping up all the time. HASS. Highly accelerated Stress Screening. This is a production test designed to find manufacturing defects, engineering changes, etc., that may affect the reliability of the product. You need some kind of environmental or HALT chamber, or you can send all your units to a lab, but that gets expensive real fast. The test is similar to HALT but you don't go to the destruct limits, just high enough to stress the unit and find defects. The limits are usually established during HALT testing Many books are available on the above subject, most notably Accelerated Reliability Engineering. HALT Hass by Greg K. Hobbs distributed by Wiley. Good Luck Darrell Locke Advanced Input Devices -Original Message- From: Dave Wilson [mailto:dwil...@alidian.com] Sent: Friday, September 08, 2000 10:34 AM To: 'emc-p...@ieee.org'; 'n...@world.std.com' Subject: HALT/HASS Testing We make a Metro DWDM product (all fiber) and one of our potential customers mentioned HALT/HASS environmental testing. Has anyone else had to go through this for similar products? Thanks, Dave Wilson Alidian Networks Inc. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: 90 V gas-filled arrestors source?
Schaffner does. They can be reached at 800-367-5566 or 732-225-9533. Dan Kinney Horner APG -Original Message- From: David Gelfand [SMTP:gelf...@memotec.com] Sent: Friday, September 08, 2000 10:07 AM To: emc-p...@majordomo.ieee.org Subject: 90 V gas-filled arrestors source? Hello group, Does anyone know who makes gas-filled arrestors called for in IEC 1000-4-5 coupling networks? Would a MOV be ok? Thanks, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
T1E1.418-2000
Anyone know where to obtain a draft copy of the new HDSL2 Interoperability standard T1E1.418-2000? I believe the document is still undergoing final revisions, but a recent draft copy would be a big help. Thanks... D -- _ DWIGHT HUNNICUTT Sr.Compliance Engineer _/_/ _/ _/_/ _/ _/_/ _/ _/_/ _/ _/ _/ _/_/ _/ _/ _/_/_/_/ _/ _/_/ _/_/_/_/_/_/ _/ _/ _/_/_/_/ T E C H N O L O G I E S 510-771-3349 520-244-2721 fax www.vina-tech.com _
RE: R: R: Conducted Emissions on Telecom Ports
All, As Ghery reported before (lost in the recent threads, but copied below), the closely related issue cf definition creepage is being addressed by CISPR SC G and is already is CDV stage but not yet FDIS. If it isn't already too late, this might be the best or only opportunity we'll get for bring the issue up for discussion in a CISPR committee within the next couple of years. This would be the opportunity to bring together in some way (?) the designers of Ethernet and the CISPR committee, so whatever the outcome we can agree the issue was examined with due engineering dilligence. Regards, Eric Lifsey Please respond to Pettit, Ghery ghery.pet...@intel.com To: Eric Lifsey/AUS/NIC@NIC, emc-p...@ieee.org cc: Subject: RE: Conducted Emissions on Telecom Ports This sort of question has already come up in CISPR SC G (the owner of CISPR 22). There is a CDV (Committee Draft for Vote) being prepared that, if adopted as a Final Draft International Standard (FDIS), will put a halt to the definition creep that has been happening with this issue. The text doesn't get rid of LANs as a telecom port, but it does prevent administrations from calling things like RS-232 (yes, Australia has tried to justify this as a telecom port), USB, 1393, etc telecom ports. Nothing happens fast in the IEC, so don't hold your breath waiting for this change to happen, but we are working on it. When the CDV comes out there will be a voting period on it and if it passes, it will then be re-issued as an FDIS for final vote. I wouldn't expect any final action for at least a year or more. Ghery Pettit Intel Member, US CISPR G TAG --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
90 V gas-filled arrestors source?
Hello group, Does anyone know who makes gas-filled arrestors called for in IEC 1000-4-5 coupling networks? Would a MOV be ok? Thanks, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada
RE: Hot Flaming Oil Test
I hope you don't live in the UK, the cost of the fuel would make the test far too expensive to perform$1.22 for a litre of diesel! Regards Chris Colgan EMC Safety TAG McLaren Audio Ltd mailto:chris.col...@tagmclarenaudio.com -Original Message- From: Kenneth McCormick [SMTP:kmccormick...@hotmail.com] Sent: 08 September 2000 15:06 To: emc-p...@majordomo.ieee.org Subject: RE: Hot Flaming Oil Test I am glad that I was able to assist in allowing Rich to earn his keep. I received several responses both public and privately...most said the same thing, it is a difficult test to conduct and comply with. Many thanks to those that responded, your advice and expertise have given me several good ideas on how to conduct the test and addressed several of the concerns (safety and repeatibility) that I had about the test. Now I'm off to purchase some Diesel... Regards, Ken From: Grant, Tania (Tania) tgr...@lucent.com Reply-To: Grant, Tania (Tania) tgr...@lucent.com To: emc-p...@majordomo.ieee.org, 'John Juhasz' jjuh...@fiberoptions.com Subject: RE: Hot Flaming Oil Test Date: Thu, 7 Sep 2000 12:43:05 -0700 So it took hot flaming oil to assess Rich's worth! _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org = Authorised on 09/08/00 at 15:50:16; code 37f48bf3F846D393. ** Please visit us at www.tagmclarenaudio.com ** The contents of this E-mail are confidential and for the exclusive use of the intended recipient. If you receive this E-mail in error, please delete it from your system immediately and notify us either by E-mail, telephone or fax. You should not copy, forward or otherwise disclose the content of the E-mail. TAG McLaren Audio Ltd The Summit, 11 Latham Road Huntingdon, Cambs, PE29 6ZU Telephone : 01480 415600 (+44 1480 415600) Facsimile : 01480 52159 (+44 1480 52159) ** Please visit us at www.tagmclarenaudio.com ** --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: UL 723
Richard is absolutely correct. It's like trying to compare a match stick to a bon fire. Regards, Peter L. Tarver, PE ptar...@nortelnetworks.com -Original Message- From: wo...@sensormatic.com I just went through this myself. There is no real correlation between UL94 flame ratings and flame spread ratings. The test methods are completely different and one cannot predict the flame spread rating from the flame rating. Richard Woods -- From: james Yoo Dear every one I have question about UL 723 Tests for surface burning characteristics of building material. What is the satisfaction flammable grade according to UL94 or UL746 If the FSI(flame spread index) is below 200. If anyone knows about that please let me know. Best regards, james Yoo jwon...@hotmail.com
RE: Hot Flaming Oil Test
I am glad that I was able to assist in allowing Rich to earn his keep. I received several responses both public and privately...most said the same thing, it is a difficult test to conduct and comply with. Many thanks to those that responded, your advice and expertise have given me several good ideas on how to conduct the test and addressed several of the concerns (safety and repeatibility) that I had about the test. Now I'm off to purchase some Diesel... Regards, Ken From: Grant, Tania (Tania) tgr...@lucent.com Reply-To: Grant, Tania (Tania) tgr...@lucent.com To: emc-p...@majordomo.ieee.org, 'John Juhasz' jjuh...@fiberoptions.com Subject: RE: Hot Flaming Oil Test Date: Thu, 7 Sep 2000 12:43:05 -0700 So it took hot flaming oil to assess Rich's worth! _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: R: R: Conducted Emissions on Telecom Ports
Paolo, You bring up an interesting point about FCC. FCC recognizes CISPR 22:1985 is as an alternative test method. The 1985 version does not specify emissions on LAN or telco. FCC Part 68 specifies conducted emissions only on mains cables over 450kHz to 30MHz with slightly different limits. There seems to be considerable interest in requesting a review of the need for conducted emissions requirements for LANS, not to mention installation cost (STP cost differential, clumsy routing, earthing considerations). What is our next step to get a formal review? David __ Reply Separator _ Subject: R: R: Conducted Emissions on Telecom Ports Author: Paolo Roncone SMTP:paolo.ronc...@compuprint.it at ADEMCONET List-Post: emc-pstc@listserv.ieee.org Date:9/8/2000 6:51 AM Ken and Cortland and many others that entered this subject : First, radiated emissions are best measured with radiated (not conducted) measurements. There is a correlation between CM currents and RE but that's not all (resonances, cable layout etc. count a lot). Second, you say that CE are easier to measure than RE ? Agree if you talk about emissions on AC power cords (as per CISPR22 and FCC part 15). But for the new requirements on telecom ports, I suggest you to take a look at the new (3.ed.) CISPR22 or EN55022 (sec. 9.5 + annex C.1) and may be you change your opinion ! Radiated emissions above 30 MHz are already covered. If you wanna take care of lower frequencies ( 30 MHz) take a loop antenna (remember the old VDE rules ?) and measure radiated H-fields with your system in the same (typical) layout used for the higher frequencies (with whatever cables you specify, UTS, STP etc.). I am sure that is much quicker, easier and repeatable than all the nonsense (ISNs, CDNs, clamps, current probes, capacitive probes, ferrites, 150 ohm resistors, signal generators, impedance measurements, voltage measurements, current measurements and more) in the new CISPR22. As for the question of outside world, I think in this ever more connected world the border line between INSIDE and OUTSIDE is getting more and more blurred, BUT I also think that a line must be drawn by the standard bodies, otherwise it's gonna really get too much confusing (hope some CISPR/CENELEC member gets it). If we spill over the line (office, floor, building... whatever), emissions requirements are triggered. But within that line it's to be considered an intra-system (what's the system ? that's another good question to be settled) interference potential and the manufacturer should take care of it without need of enforcement because he has all the interest in making a product (system) that works properly and reliably. One last point: based on David Sterner's note, looks to me that North America has a pretty extensive Ethernet and-the-like network. I honestly don't know if the FCC has already enforced emission limits on LAN ports. Anyway, based on David's note looks like there are no complaits of interference with TV and telephones. And please note, this is the very bottom line of it. Emission limits should be intended to protect public services ... and physics works the same on both sides of the Atlantic... or not My personal opinion ... Paolo -Messaggio originale- Da: Ken Javor [SMTP:ken.ja...@emccompliance.com] Inviato: giovedì 7 settembre 2000 18.43 A: Paolo Roncone; 'eric.lif...@ni.com' Cc: 'emc-p...@ieee.org' Oggetto: Re: R: Conducted Emissions on Telecom Ports Although I don't work commercial EMC on a regular basis and I do not know over what frequency range the telecom port CE are controlled (I assume here 150 kHz - 30 MHz), I believe that there is a mistaken premise inherent in the comments to which I am responding. The purpose of controlling common mode CE on any port is not to protect equipment at the other end of the cable, or other co-sited cables, but rather to control radiated emissions in a frequency range in which CE are easier to measure than RE. In turn, the purpose of controlling RE is to protect broadcast radio reception. -- From: Paolo Roncone paolo.ronc...@compuprint.it To: 'eric.lif...@ni.com' eric.lif...@ni.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: R: Conducted Emissions on Telecom Ports Date: Thu, Sep 7, 2000, 9:45 AM Hi Eric, I 100% agree with you. The scope of emissions standard should be to protect the outside (i.e. public) environment from interference. So only ports that connect to public telecom networks should be covered by the standard. The problem is (as pointed out in one of the previous notes) that the new CISPR22 / EN55022 standard clearly includes LAN ports in the definition of telecommunications ports (section 3.6) no matter
Hacking of RCIC
Article in Tech News about the hacker. http://technews.netscape.com/news/0-1005-200-2722466.html?tag=st.ne.1002.tgif.ni Apparently he hacked many sites to spread his message. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: R: Conducted Emissions on Telecom Ports
Ken, that is not what Mike is saying. Mike's statment was to the effect that if the noise can get out of the EUT then noise from another source can get in. A point of exit can also be a point of entry for EMI. This applies to all types of launching mechanisms, not just cables. Also, just because a piece of equipemnt is passing CE or any emissions does not guarrenty that it will not cause a problem with other equipment. Coupling between adjacent cabling can cause EMC issues even if both unit pass CE. Primarily, all emissions limits, CE and RE, exist to provide a level of protection for communitcations over the air. Equipment protection is secondary. Keeping equipment clean at the source goes a long way to protect it from outside influences. Guy Story, KC5GOI Compliance Technician Interphase Corporation Dallas Texas phone: 214.654.5161 fax: 214.654.5406 - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: michael.sundst...@nokia.com; paolo.ronc...@compuprint.it; eric.lif...@ni.com Cc: emc-p...@ieee.org Sent: Thursday, September 07, 2000 10:17 PM Subject: Re: R: Conducted Emissions on Telecom Ports So you are saying that an emission limit was imposed to improve immunity of the self-same equipment? I have to go on record disagreeing with that interpretation. As for protection of nearby circuits, my guess is that if you calculate coupling from a cable just meeting your telecom port CE limit to an adjacent cable, you will find that even common mode coupling is orders of magnitude below the intentional signal carried in the adjacent victim cable. I say this in full ignorance of just what that CE limit is, since I know that a CE limit designed to protect against rfi will more than protect against cable-to-cable coupling. -- From: michael.sundst...@nokia.com To: ken.ja...@emccompliance.com, paolo.ronc...@compuprint.it, eric.lif...@ni.com Cc: emc-p...@ieee.org Subject: RE: R: Conducted Emissions on Telecom Ports Date: Thu, Sep 7, 2000, 5:01 PM Actually it's to reduce interference to one's own equipment, (if it emits it - it's also susceptible to it). It also has the effect of reducing interference to other near by equipment. Michael Sundstrom Nokia Mobile Phones, PCC EMC Technician cube 4E : 390B phone: 972-374-1462 mobile: 817-917-5021 michael.sundst...@nokia.com amateur call: KB5UKT --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Safety of mobile phones.
It can be found at http://europa.eu.int/comm/enterprise/electr_equipment/lv/rec519.pdf http://europa.eu.int/comm/enterprise/electr_equipment/lv/rec519.pdf Richard Woods -- From: Allan G. Carr [SMTP:e...@agctel.co.uk] Sent: Thursday, September 07, 2000 3:47 PM To: emc-p...@ieee.org Subject: Safety of mobile phones. Can anyone please point me towards a copy of the Official Journal of the European Communities Council Recommendation 1999/519/EC dated 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz). I have checked the EC OJ site but it is no longer available. Thanks in anticipation Allan -- Allan G.Carr B.Sc.(Elec.Eng) AMIEE | AGC-Tel Consultants Ltd Telecommunications Consultant | Tel: +44(0)141-956-2506 European Approvals Specialist | Fax: +44(0)141-956-5347 62 Crawford Road, Milngavie | Voice Mail: +44(0)1252-30-3062 Glasgow, G62 7LF, Scotland | http://www.agctel.co.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: SAR
Intertek Testing Services in Menlo Park, CA. can do the SAR tests. They can be reached at ph 650-463-2900 fax 650-463-2910 or find them through the web site www.etlsemko.com. Bob Martin, PE, NCE Sr. Technical Manager Intertek Testing Services http://www.etlsemko.com (978)263-2662 fax(978)263-7086 r...@itsqs.com -Original Message- From: ron_cher...@densolabs.com [mailto:ron_cher...@densolabs.com] Sent: Thursday, September 07, 2000 6:05 PM To: emc-p...@ieee.org Subject: SAR I am trying to get a list of labs that can perform SAR testing on the West Coast, (CA). Thanks, Ron DENSO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Near field measurements
Mr Woods 1) I've never used a lab for these tests so I can't help there. 2) Several outfits make/sell these probes - all isotropic: Narda Microwave East (Mr. Johnson), Holaday Indutries (Ms. Turja), and Wandel-Golterman, (absorbed by Chase, absorbed by Schaffner absorbed by Narda???), Mr. Berezny (@Chase Systems). For 2.45GHz, 12cm lambda, near-field is closer to 2cm, and these probes all seem to have a balloon of ~5cm radius at the end, so they won't help. But if you just mean measuring the field 'near' the source then, sure, they're OK. Prices from $8k to $10k for a full E and H kit. 3) I've leased directly from Holaday, but I would also suggest shopping around; maybe Rentelco, or ITERents? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
R: R: Conducted Emissions on Telecom Ports
Ken and Cortland and many others that entered this subject : First, radiated emissions are best measured with radiated (not conducted) measurements. There is a correlation between CM currents and RE but that's not all (resonances, cable layout etc. count a lot). Second, you say that CE are easier to measure than RE ? Agree if you talk about emissions on AC power cords (as per CISPR22 and FCC part 15). But for the new requirements on telecom ports, I suggest you to take a look at the new (3.ed.) CISPR22 or EN55022 (sec. 9.5 + annex C.1) and may be you change your opinion ! Radiated emissions above 30 MHz are already covered. If you wanna take care of lower frequencies ( 30 MHz) take a loop antenna (remember the old VDE rules ?) and measure radiated H-fields with your system in the same (typical) layout used for the higher frequencies (with whatever cables you specify, UTS, STP etc.). I am sure that is much quicker, easier and repeatable than all the nonsense (ISNs, CDNs, clamps, current probes, capacitive probes, ferrites, 150 ohm resistors, signal generators, impedance measurements, voltage measurements, current measurements and more) in the new CISPR22. As for the question of outside world, I think in this ever more connected world the border line between INSIDE and OUTSIDE is getting more and more blurred, BUT I also think that a line must be drawn by the standard bodies, otherwise it's gonna really get too much confusing (hope some CISPR/CENELEC member gets it). If we spill over the line (office, floor, building... whatever), emissions requirements are triggered. But within that line it's to be considered an intra-system (what's the system ? that's another good question to be settled) interference potential and the manufacturer should take care of it without need of enforcement because he has all the interest in making a product (system) that works properly and reliably. One last point: based on David Sterner's note, looks to me that North America has a pretty extensive Ethernet and-the-like network. I honestly don't know if the FCC has already enforced emission limits on LAN ports. Anyway, based on David's note looks like there are no complaits of interference with TV and telephones. And please note, this is the very bottom line of it. Emission limits should be intended to protect public services ... and physics works the same on both sides of the Atlantic... or not My personal opinion ... Paolo -Messaggio originale- Da: Ken Javor [SMTP:ken.ja...@emccompliance.com] Inviato:giovedì 7 settembre 2000 18.43 A: Paolo Roncone; 'eric.lif...@ni.com' Cc: 'emc-p...@ieee.org' Oggetto:Re: R: Conducted Emissions on Telecom Ports Although I don't work commercial EMC on a regular basis and I do not know over what frequency range the telecom port CE are controlled (I assume here 150 kHz - 30 MHz), I believe that there is a mistaken premise inherent in the comments to which I am responding. The purpose of controlling common mode CE on any port is not to protect equipment at the other end of the cable, or other co-sited cables, but rather to control radiated emissions in a frequency range in which CE are easier to measure than RE. In turn, the purpose of controlling RE is to protect broadcast radio reception. -- From: Paolo Roncone paolo.ronc...@compuprint.it To: 'eric.lif...@ni.com' eric.lif...@ni.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: R: Conducted Emissions on Telecom Ports Date: Thu, Sep 7, 2000, 9:45 AM Hi Eric, I 100% agree with you. The scope of emissions standard should be to protect the outside (i.e. public) environment from interference. So only ports that connect to public telecom networks should be covered by the standard. The problem is (as pointed out in one of the previous notes) that the new CISPR22 / EN55022 standard clearly includes LAN ports in the definition of telecommunications ports (section 3.6) no matter if they connect to the outside world or not. Regards, Paolo Roncone Compuprint s.p.a. Italy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Farewell.
Dear all, for two years I've been focusing all my efforts and neuronal juice to Advanced Shielding Technologies. Though I'm not an engineer, I studied three years Electronics Engineering but left it. I used to fail on Physics... and used to hate it too. Anyway, I've learnt mucho more physic laws, strange effects working on EMC than when I studied. And I really like this all right now. Advanced Shielding Technologies and you all have taught me some very interesting things which I have enjoyed a lot (though some times my inbox spilled over the brim). I just want to inform you all I'm leaving this engineering/sorcerer world, where sometimes equations are not useful and experience and common sense is what works. Thank you very much. May the (magnetic) force be with you ;-) David Monreal Product Manager www.itbunker.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: SAR
Hi Ron, I believe Elliott Labs in Sunnyvale, CA does such testing and have a very good customer focus. Doug ron_cher...@densolabs.com wrote: I am trying to get a list of labs that can perform SAR testing on the West Coast, (CA). Thanks, Ron DENSO --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org -- --- ___ _ 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 EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Conducted Emissions on Telecom Ports
Hi All, I could not resist adding my two cents worth. In the last several years I spent at Bell Labs in NJ (moved to CA 4 1/2 years ago), part of my funding came from a group that was responsible for UTP (Cat 5) and associated hardware. On immunity performance, we were not able to find a shielded system that would outperform UTP using the interface circuits I had design input on. (When I first proposed the circuitry, the group had an internal Bell Labs balun expert review it. He did not understand how it worked.) Emissions were lower compared to several shielded systems we measured. The data was published at EMC Roma about 1995. If I can dig it up, I will try to post it to my site later this month. Several formats of data were used including 100 Mb speeds. We even did a demonstration of a 600 Mb over UTP cable (section of the cable is within sight at this moment). The conducted emissions on telecom leads spec was just being written at that time. As I recall, we were pretty close to meeting it except the method in the proposed standard was not workable, so we used current probes and moving the cables to maximize current (just like RE testing). The net result is that UTP with the appropriate interface circuits (not expensive, either) performs quite well compared to STP systems. If anyone wants more into, email directly to me and I will try and hook them up with someone at Bell Labs in NJ who is currently on the project. It's been a while and I am not sure what the present status of that work is. BTW, I recall that starting with a VERY well balanced source/load, Cat5 cable inherently had about 12 dB better balance, and therefore performance, than Cat3 for the high frequency immunity/radiated measurements that I made. I did not get much into the signal transmission differences between Cat3 and Cat5 though. Doug Gary McInturff wrote: Another little nagging problem exists. Without going into the whole historically precedence UTP was a pretty important reason why ethernet was adopted so widely. The wiring was pretty much in place because of the cables that had been run for connecting office telephones etc. People don't want to drag in new cables (STP) because of the cost. I happen to agree with you assements below and wouldn't even consider UTP if it weren't for the existing installs and the 805 standard that (prefers?) it. Thanks Gary -Original Message- -- --- ___ _ 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 EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Safety of mobile phones.
Can anyone please point me towards a copy of the Official Journal of the European Communities Council Recommendation 1999/519/EC dated 12 July 1999 on the limitation of exposure of the general public to electromagnetic fields (0 Hz to 300 GHz). I have checked the EC OJ site but it is no longer available. Thanks in anticipation Allan -- Allan G.Carr B.Sc.(Elec.Eng) AMIEE | AGC-Tel Consultants Ltd Telecommunications Consultant | Tel: +44(0)141-956-2506 European Approvals Specialist | Fax: +44(0)141-956-5347 62 Crawford Road, Milngavie | Voice Mail: +44(0)1252-30-3062 Glasgow, G62 7LF, Scotland | http://www.agctel.co.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
