RE: Ethernet coax connection
Rich, I think you must be correct. I do have anecdotal evidence of persons being knocked on their butts by grabbing hold of an Ethernet coax in a large facility and trying to connect it to a computer. My experience is in EMC and the 10Base2 Ethernet (coax) is a persistent offender. (Actually, the twisted pair stuff has its own set of EMC problems.) Regards, Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Wednesday, March 05, 2003 4:31 PM To: Knighten, Jim L Cc: ken.ja...@emccompliance.com; emc-p...@majordomo.ieee.org Subject:Re: Ethernet coax connection Hi Jim: It is a potential shock hazard if the coax run is long and runs from building to building (for instance) where the ground potentials may be different in the different buildings. One can develop a large potential on the shield of the cable, so that if you put yourself between the cable shield and ground you may get a strong shock. That is the reason for isolating the shield from more than one direct connection to ground. It is a real issue. I don't believe the issue is that of electric shock. I don't believe the current and resistance of the neutral are high enough to develop 30 volts (the shock hazard limit). Instead, I believe the problem is that, with two connections, the shield is in parallel with the neutral. That means that some of the neutral current will pass through the shield, and will likely open a PWB trace somewhere. In the process, the PWB trace heating may start a fire. I believe the circuit is: (You may not be able to read this schematic if your mail reader is not set for plain ASCII text.) L Bldg A +-++ | || | || | | | | (~) 120 V | | | load | | | | | || |N|| +-++-+-+ |utility | || Bldg A | |ground | || ground | |rod | || rod |PE BNC shield - | | - ++ ---| | --- | - | |-| | | | | | | | | | | | L Bldg B | ++| ||| ||| | | | | | | | load | | | | | ||| | N || ++-+-+| | Bldg B | | | ground | | | rod |PE| - ++ --- BNC shield - You can see from the schematic that the shield is in parallel with both the neutral and the earth-ground. Being in parallel, it will carry some of the neutral current, depending on the respective resistances. Because of both the neutral and the earth-ground, the voltage should never approach 30 volts (1/4 of the mains voltage). But, there can be a very high current in the shield of the BNC cable. Best regards, Rich 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: davehe...@attbi.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: FDA Laser Requirements
Rich - An on-line search of those available (back to 1996) at the GPO web site shows no sign of 1002.61. However, my paper copy dated 1993 shows 1002.61 is the first subparagraph of Subpart G, Codes for Reporting Listed Electronic Products, and 1002.61 is titled, List of specific product groups. I can provide a scanned copy to those who wish it. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com -Original Message- From: richwo...@tycoint.com Sent: Wednesday, March 05, 2003 8:56 AM 21CFR1002.30(b) refers to 1002.61 which does not exist. Does anyone know the correct reference? Richard Woods Sensormatic Electronics Tyco International 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: davehe...@attbi.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: Ethernet coax connection
Ken, It depends if compliance with the Ethernet standard is important to you. If you connect to anyone else's network where someone else may be dealing with a coax that is grounded on your end, then it is probably important. If not, then it may not matter. This is a product safety issue. I have used 10BaseT (10 Megabit twisted pair Ethernet) in which we shield on both ends within our system. Whatever goes out to the world is not grounded on either end. I am assuming from your messages that this may be a military system, so the product safety rules may be different than for commercial equipment. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 1:09 PM To: Robert Macy; emc-p...@ieee.org Subject:Re: Ethernet coax connection If all the ac equipment is powered by the same local source, and all the ac powered equipment is case-grounded within the same rack, is it correct to assume that the safety issue is moot? That is, can I then use a grounded bnc connector at both ends? on 3/5/03 4:02 PM, Robert Macy at m...@california.com wrote: It is my understanding there is a spec relating to both the voltage handling capability and the impedance between ethernet coax and earth ground. At low frequency (must be more than a certain level) it is quite high in order to prevent potentially damaging ground loops from forming. At high frequency (must be less than a certain level) to effectively reference the shield to chassis potential and make certain that the coax doesn't radiate. There are manufacturers that sell coax panel connectors with the proper built in capacitor. I recall $10 each price tag. I further recall that we used to use 0.001uF 2kV caps. WELL DRESSED AND MOUNTED EXTREMELY PROPERLY. Vaguely remember that the impedance was to be more than 1Meg at 60Hz and less than 50 at 3MHz, but you should check the ethernet spec. You can tell a lot about the cap's mounting (and quality) by looking at the spectrum of the radiated emissions. For example, internal clock and the cap is referenced to a noisy spot. Or, spectrum related to the ethernet traffic and a loop exists around the coax terminations and bypass cap. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: emc-p...@majordomo.ieee.org Sent: Wednesday, March 05, 2003 12:37 PM Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 -- 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: davehe...@attbi.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: davehe...@attbi.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:
E26/E27 Lamp-Base
Hi, Does anybody know the differences between E26 and E27(lamp base)? Thanks. Regards, Carl Yi 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: davehe...@attbi.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: Ethernet coax connection
we've had good success with the built capacitance of 9000pf as well, depending on test being discussed and frequency, certain cap. values from the shielded ring of the UNgrounded ring to earth works well for low freq.. 30 mhz. Richard, From: Knighten, Jim L [mailto:jk100...@teradata-ncr.com] Sent: Wednesday, March 05, 2003 4:12 PM To: Ken Javor; emc-p...@majordomo.ieee.org Subject: RE: Ethernet coax connection Ken, It is a potential shock hazard if the coax run is long and runs from building to building (for instance) where the ground potentials may be different in the different buildings. One can develop a large potential on the shield of the cable, so that if you put yourself between the cable shield and ground you may get a strong shock. That is the reason for isolating the shield from more than one direct connection to ground. It is a real issue. The result for EMI is, as you have noted, the creation of an egregious EMI offender. I have used the chassis mounted BNC connectors with built-in capacitors successfully. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:58 PM To: Knighten, Jim L; emc-p...@majordomo.ieee.org Subject:Re: Ethernet coax connection Assume complete ignorance on my part. What is the safety concern? on 3/5/03 3:50 PM, Knighten, Jim L at jk100...@teradata-ncr.com wrote: Ken, Safety considerations are the reason for the spec requirement. You are allowed to ground the shield at one point. Try using a BNC coax connector with a built-in capacitor to ground. That gives you an AC connection to ground and is often quite effective. These are off-the-shelf parts. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:38 PM To: emc-p...@majordomo.ieee.org Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: davehe...@attbi.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: davehe...@attbi.com For policy questions, send mail to: Richard Nute:
RE: Ethernet coax connection
Ken, It is a potential shock hazard if the coax run is long and runs from building to building (for instance) where the ground potentials may be different in the different buildings. One can develop a large potential on the shield of the cable, so that if you put yourself between the cable shield and ground you may get a strong shock. That is the reason for isolating the shield from more than one direct connection to ground. It is a real issue. The result for EMI is, as you have noted, the creation of an egregious EMI offender. I have used the chassis mounted BNC connectors with built-in capacitors successfully. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:58 PM To: Knighten, Jim L; emc-p...@majordomo.ieee.org Subject:Re: Ethernet coax connection Assume complete ignorance on my part. What is the safety concern? on 3/5/03 3:50 PM, Knighten, Jim L at jk100...@teradata-ncr.com wrote: Ken, Safety considerations are the reason for the spec requirement. You are allowed to ground the shield at one point. Try using a BNC coax connector with a built-in capacitor to ground. That gives you an AC connection to ground and is often quite effective. These are off-the-shelf parts. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:38 PM To: emc-p...@majordomo.ieee.org Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: davehe...@attbi.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
Fw, Yahoo Groups Recommendation?: Changes to IEEE emc-pstc web-based services...
Jim/Richard; Any update on the data transfer from http://ieeepstc.mindcruiser.com/ http://ieeepstc.mindcruiser.com/ to ttps://www.ieeecommunities.org/emc-pstc https://www.ieeecommunities.org/emc-pstc... or a tentative date? For your information... the Yahoo group http://groups.yahoo.com/group/emc-pstc/ http://groups.yahoo.com/group/emc-pstc/ can be easily configured to operate both as a listserver-based service and a web-based service. As a web-based service, https://www.ieeecommunities.org/emc-pstc https://www.ieeecommunities.org/emc-pstc does offer some advantages over Yahoo Groups (as referenced below)... but as a listserver-based service, it's advantage over majordomo is that it allows the member to control the delivery of messages (ie, individual emails, daily digest or no email) and messages can be viewed online http://groups.yahoo.com/group/emc-pstc/messages. I would recommend that you consider a migration to Yahoo Groups, once the data transfer to https://www.ieeecommunities.org/emc-pstc https://www.ieeecommunities.org/emc-pstc is complete. Should the planned data transfer be not possible, you may want to consider a full migration to Yahoo Groups, as listserver/web-based solution. Here in Ottawa, Canada... we have a group called RAFT - Regulatory Approvals Forum for Technology, and have been using Yahoo Groups http://groups.yahoo.com/group/RAFT-Global/ http://groups.yahoo.com/group/RAFT-Global/ for the past 2 years. I have joined http://groups.yahoo.com/group/emc-pstc/ http://groups.yahoo.com/group/emc-pstc/ some time ago... If you want to give it some consideration, I can volunteer to make the additional configuration changes. Please let me know your thought, and the Group owner will need to have me assigned as Moderator. Regards, http://ca.geocities.com/guyboone/My_Page.html Guy Boone, P. Eng Electrical Engineer, specializing in Safety Compliance, Power/Control Systems Design Buildings Engineering Steering Committee Member - http://www.raft-global.org/ www.RAFT-Global.org 35 Athena Way Tel: 613-823-7534 Ottawa (Nepean), ON K2G 6S1 Cell: 613-850-6533 From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Jim Bacher Sent: January 23, 2003 10:54 AM To: 'Andre, Pierre-Marie'; emc-p...@majordomo.ieee.org Subject: RE: EMC-PSTC Email Forum We have had a couple major glitches with the movement of data. We are working on an alternate solution to the issue. As soon as we have worked out the details we will let you know. Jim From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Andre, Pierre-Marie Sent: January 23, 2003 4:24 AM To: emc-p...@majordomo.ieee.org Subject: EMC-PSTC Email Forum On the http://www.ewh.ieee.org/soc/emcs/pstc/index.html http://www.ewh.ieee.org/soc/emcs/pstc/index.html I can read : The EMC-PSTC archives will be moved to another site shortly. The new location will be announced shortly. Make sure you check here often. Is there any target date to make the new location available? Many thanks for your answer This forum is really useful Pierre-Marie Andre Senior Approval Engineer From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Rich Nute Sent: January 2, 2003 12:22 PM To: Product Safety Technical Committee Cc: Jim Bacher; mg.ca...@ieee.org Subject: The listserver WILL continue. Thank you for all the comments on the listserver-based service versus the web-based service. The IEEE listserver WILL continue. I apologize for not being clear on this point. We started with listserver service. However, the listserver does not satisfy all of the needs of our subscribers. So, we supplement the listserver with a web service. Some of our supplemental needs: 1. Archive of listserver messages, with a search function. 2. A means for providing papers that cannot be sent via the listserver due to size limitations. 3. A means for announcing local chapter activities without sending the notice worldwide. 4. A means for selective messaging (to eliminate non-pertinent messages from your inbox). 5. A means for providing papers of both general interest and highly-specialized interest. 6. A means for reporting IEEE EMC Society and emerging Product Safety Society activity. 7. A means for threaded discussions. etc. The ideal scheme would include all of this in a single integrated scheme. As explained in my previous message, for the moment we do not have this capability. Both the listserver service and the web-based service provide discussions. Therein lies the problem: Two discussion groups, with no connection between them. The listserver discussions are readily transmitted over all forms of connections. The web-based discussions are largely impractical for slow (telephone) connections. We recognize this. For the moment, we have two discussion services. Your usage of each
Re: Ethernet coax connection
Jim, Thank you! That took care of my concern. Ken on 3/5/03 4:11 PM, Knighten, Jim L at jk100...@teradata-ncr.com wrote: Ken, It is a potential shock hazard if the coax run is long and runs from building to building (for instance) where the ground potentials may be different in the different buildings. One can develop a large potential on the shield of the cable, so that if you put yourself between the cable shield and ground you may get a strong shock. That is the reason for isolating the shield from more than one direct connection to ground. It is a real issue. The result for EMI is, as you have noted, the creation of an egregious EMI offender. I have used the chassis mounted BNC connectors with built-in capacitors successfully. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:58 PM To: Knighten, Jim L; emc-p...@majordomo.ieee.org Subject: Re: Ethernet coax connection Assume complete ignorance on my part. What is the safety concern? on 3/5/03 3:50 PM, Knighten, Jim L at jk100...@teradata-ncr.com wrote: Ken, Safety considerations are the reason for the spec requirement. You are allowed to ground the shield at one point. Try using a BNC coax connector with a built-in capacitor to ground. That gives you an AC connection to ground and is often quite effective. These are off-the-shelf parts. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:38 PM To: emc-p...@majordomo.ieee.org Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: davehe...@attbi.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: Ethernet coax connection
If all the ac equipment is powered by the same local source, and all the ac powered equipment is case-grounded within the same rack, is it correct to assume that the safety issue is moot? That is, can I then use a grounded bnc connector at both ends? on 3/5/03 4:02 PM, Robert Macy at m...@california.com wrote: It is my understanding there is a spec relating to both the voltage handling capability and the impedance between ethernet coax and earth ground. At low frequency (must be more than a certain level) it is quite high in order to prevent potentially damaging ground loops from forming. At high frequency (must be less than a certain level) to effectively reference the shield to chassis potential and make certain that the coax doesn't radiate. There are manufacturers that sell coax panel connectors with the proper built in capacitor. I recall $10 each price tag. I further recall that we used to use 0.001uF 2kV caps. WELL DRESSED AND MOUNTED EXTREMELY PROPERLY. Vaguely remember that the impedance was to be more than 1Meg at 60Hz and less than 50 at 3MHz, but you should check the ethernet spec. You can tell a lot about the cap's mounting (and quality) by looking at the spectrum of the radiated emissions. For example, internal clock and the cap is referenced to a noisy spot. Or, spectrum related to the ethernet traffic and a loop exists around the coax terminations and bypass cap. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 - Original Message - From: Ken Javor ken.ja...@emccompliance.com To: emc-p...@majordomo.ieee.org Sent: Wednesday, March 05, 2003 12:37 PM Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 -- 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: davehe...@attbi.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: Ethernet coax connection
Assume complete ignorance on my part. What is the safety concern? on 3/5/03 3:50 PM, Knighten, Jim L at jk100...@teradata-ncr.com wrote: Ken, Safety considerations are the reason for the spec requirement. You are allowed to ground the shield at one point. Try using a BNC coax connector with a built-in capacitor to ground. That gives you an AC connection to ground and is often quite effective. These are off-the-shelf parts. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:38 PM To: emc-p...@majordomo.ieee.org Subject: Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: davehe...@attbi.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: Ethernet coax connection
Ken, Safety considerations are the reason for the spec requirement. You are allowed to ground the shield at one point. Try using a BNC coax connector with a built-in capacitor to ground. That gives you an AC connection to ground and is often quite effective. These are off-the-shelf parts. Jim Jim Knighten, Ph.D. Teradata, a Division of NCR http://www.ncr.com 17095 Via Del Campo San Diego, CA 92127 USA Tel: 858-485-2537 Fax: 858-485-3788 jim.knigh...@ncr.com -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, March 05, 2003 12:38 PM To: emc-p...@majordomo.ieee.org Subject:Ethernet coax connection Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: davehe...@attbi.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
Ethernet coax connection
Question for list members: Background: I am troubleshooting a complex integration of military hardware and COTS. One COTS piece of equipment has an RG-58 coaxial connection, but the coax connector is an isolated feedthrough bnc. From a radiated emissions point-of-view, that is hurting us. One of the engineers here said that is part of the spec - Ethernet shields are not supposed to be chassis grounded. Question: Can someone please explain the reason for that, and how this is usually handled to minimize radiated emissions? Thank you. 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: davehe...@attbi.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: VDE 0100 Part 253, VDE 0298 Part 4
I read in !emc-pstc that John Barnes jrbar...@iglou.com wrote (in 3e662c8b.7...@iglou.com) about 'VDE 0100 Part 253, VDE 0298 Part 4' on Wed, 5 Mar 2003: Do you know if there are any changes in the ampacity tables of BS 7671 between the 1992 and the 2001 editions? I'm not sure about 2001, but there were red faces all round about 3 months ago about the rating of 2.5 mm squared flat twin and earth, because it was inconsistent with the breaker rating for ring-mains. IIRC, the basic 'ampacity' (a term not used in British English) was increased from 21 to 22 A. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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: FDA Laser Requirements
The FDA says the correct reference is 1002.31. -Original Message- From: WOODS, RICHARD Sent: Wednesday, March 05, 2003 11:56 AM To: 'emc-pstc' Subject: FDA Laser Requirements 21CFR1002.30(b) refers to 1002.61 which does not exist. Does anyone know the correct reference? Richard Woods Sensormatic Electronics Tyco International 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: davehe...@attbi.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
Need 230VAC-115VAC 500VA Step-down Isolation Transformer with UL, cUL, and CE
I read in !emc-pstc that Bill Johnson bi...@kryotech.com wrote (in e853e3e85cf50a4f88d6aa80d9ab2c01624...@mail.conterra.com) about 'Need 230VAC-115VAC 500VA Step-down Isolation Transformer with UL, cUL, and CE' on Wed, 5 Mar 2003: Any advice on where to look or how to select such a component would be a great help! When asking about suppliers, it's a good idea to say which country you are in, and if it's a big country, roughly where within it. Also, do you want one transformer or ten thousand? You appear to be in USA, from your posting time, so, if you need only a few, have you tried Newark/Farnell? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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: VDE 0100 Part 253, VDE 0298 Part 4
John, Thank you for the tip on BS 7671. Techstreet wants $215 for BS 7671:2001, which is a bit too much for my budget when the ampacity tables are all that I am looking for. (I've already ordered over $1017 in engineering books and standards this week-- my mailman is going to hate me, having to deliver 27 heavy books if all the orders go through.) But I found a used copy of P. Cook's Commentary on BS 7671:1992 Requirements for Electrical Installations on Amazon.com for $30 plus shipping, so I ordered it. Do you know if there are any changes in the ampacity tables of BS 7671 between the 1992 and the 2001 editions? Thanks! John Barnes KS4GL, PE, NCE, ESDC Eng, SM IEEE dBi Corporation http://www.dbicorporation.com/ Woodgate wrote: I read in !emc-pstc that John Barnes jrbar...@iglou.com wrote (in 3e64d54d.7...@iglou.com) about 'VDE 0100 Part 253, VDE 0298 Part 4' on Tue, 4 Mar 2003: I am researching the ampacity (current-carrying capacity, Leitung in German) of wires for Appendix F of my book, Robust Electronic Design Reference. BS 7671 (the UK version of IEC 60364) has a lot of information on this subject. I suspect it's also in IEC 606364, but I haven't looked. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: davehe...@attbi.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: davehe...@attbi.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
FDA Laser Requirements
21CFR1002.30(b) refers to 1002.61 which does not exist. Does anyone know the correct reference? Richard Woods Sensormatic Electronics Tyco International 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: davehe...@attbi.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: programmable electronic loads; is load noise something to wat ch f or?
CONFLICT OF INTEREST NOTICE: my employer makes component SMPSs A common problem, often perceived as noise, is when the control loop of the electronic load is operating at a beat frequency of one of the SMPS control loops. I typically use a quality (X/Y-rated) cap from the load test-power terminal to the chassis of the load to reduce/eliminate this problem. If you are doing noise SMPS noise output measurements, valid data can only be acquired using discrete resistive loads. with a z-match network to the measuring device. EUT connect hardware is very important. In general, radiated noise has never been a problem with any load mfr; but I have had problems with some mfrs that had conducted noise problems at some combinations of current and voltage. At lease one load mfr tests for load-side conducted emissions by using the load to sink a pure linear power source. This spec can be difficult to extract from the mfr's documentation. Load-induced noise, for most name-brand mfrs and for my experience, has not been significant for testing either linear or SMPSs, WHEN operating within the rated voltage and current ratings of the load. Remember that the actual load element is a linear device, and linear stuff, when properly designed, is very quiet. I suppose that thermal noise for some components can be significant. But one should assume a decent load design would take this into consideration... An important spec is the compliance V. At low currents, some electronic loads are not stable when the applied V approaches the rated min input. Finally, much of an electronic load's noise figure can come from user configuration; e.g., constant-V vs constant-I mode, external V control stabilitiy, user connection technique from EUT to load, computer-generated noise (mostly form cheap GPIB cables), etc. If the p.s. swamps load-induced noise, it's probably time to evaluate the next p.s. mfr in the queue... R/S, Brian O'Connell Taiyo Yuden (USA), Inc. we are looking into purchasing a programmable DC electronic load tester for evaluating SMPS. The mainframe unit with one module will provide app. 1200W of loading. Features include constant current and constant resistance modes. Agency claims include CE Class A. How is this type of equipment tested for emissions on the input side? Having never used such a device, I am curious to know if we should be specifying a particular noise figure or parameter in our search. Intuitively, it seems to me there would be some small amount of unwanted noise generated by the excitation of the representative loading components. Wouldn't thermally generated noise be worth considering, or is this negligible? Maybe the output noise of most SMPS swamps out typical electronic load noise?
RE: Class 2 laser
IEC825-1 and CDRH requirements are focused on the laser product and incorporating provisions in the product for a safe installation. However, they do not include much on the actual installation and use/human interaction (other than for laser light shows). I recommend that you review NFPA115 - criteria for the safe design, manufacture, installation, and use of lasers and associated equipment. Bill Bisenius EDD bi...@productsafet.com www.productsafeT.com -Original Message- From: Ronald R. Wellman [mailto:rwell...@wellman.com] Sent: Monday, March 03, 2003 6:55 PM To: richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject:Re: Class 2 laser Hello Richard, Have you taken a look at 21 CFR 1040? The FDA/CDRH has certain compliance requirements for laser systems and laser products. Best regards, Ron Wellman At 03:16 PM 3/3/2003 -0500, richwo...@tycoint.com wrote: Are any national restrictions on the use of a Class 2 laser in areas where the general public would be exposed? A good example would be a beam across a doorway to detect entry and exit. Assume the product is fully compliant with IEC 60825-1. Richard Woods Sensormatic Electronics Tyco International 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: davehe...@attbi.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: VDE 0100 Part 253, VDE 0298 Part 4
I read in !emc-pstc that John Barnes jrbar...@iglou.com wrote (in 3e64d54d.7...@iglou.com) about 'VDE 0100 Part 253, VDE 0298 Part 4' on Tue, 4 Mar 2003: I am researching the ampacity (current-carrying capacity, Leitung in German) of wires for Appendix F of my book, Robust Electronic Design Reference. BS 7671 (the UK version of IEC 60364) has a lot of information on this subject. I suspect it's also in IEC 606364, but I haven't looked. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! 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: davehe...@attbi.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: E.S. of plastic xstr case
Dear John: Well, maybe not the ten millionth, but at least the umpteenth! We are an A2LA Accredited Lab in Washington State ( in the quiet country midway between Seattle and Vancouver, British Columbia). Wyle indeed works here, and is quite proficient at EMI mitigation. During coffee breaks I can see him from my office window -- running and frolicking with Eagles, Cattle, and yes, occasionally other Coyotes. Cheers, Jim Ericson I read in !emc-pstc that Jim Ericson jde...@nas.com wrote (in 003c01c2e1fb$239b0cc0$b4663fce@pavilion) about 'E.S. of plastic xstr case' on Mon, 3 Mar 2003: Jim Ericson Acme Testing Company Acme, Washington j...@acmetesting.com Do you employ Wyle E Coyote or is he an independent test-house? (;-) Am I the ten millionth person who asked? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk 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: davehe...@attbi.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: RADIATED IMMUNITY - Some Actual Measurements of FS
Dave: I agree with your comments re: testing at 10 V/m, and then falling back to 3 V/m if there is a problem. This is a good way for a client to get almost free margin-testing data. I recommend it often to our clients. If you test to 3 V/m, you don't have a clue as to what would happen at 3.1 V/m. I had to chuckle at your 40 Watt fluorescent tube story! Back in the olden days (as Chief Engineer of a 5000 Watt AM Broadcast station in California, I would often make antenna tuning adjustments with a screwdriver in one hand, and a 4-foot fluorescent bulb in the other. This is REAL RF Engineering! And yes, I work 160 meters too. Regards, Jim Ericson (KG6EK) Acme Testing Company Acme, Washington j...@acmetesting.com From: drcuthbert drcuthb...@micron.com To: emc-p...@majordomo.ieee.org Sent: Tuesday, March 04, 2003 7:05 AM Subject: RE: RADIATED IMMUNITY - Some Actual Measurements of FS Why not blast the DUT with 10V/m at all frequencies? If it misbehaves in the 3V/m bands then 3V/m could be tried. If you want some high E-field try my house (or another ham's house). I often run fields to the FCC safety limit in my house. When operating 160 meters I can light a 40 watt fluorescent tube by holding it in my hand at the operating position. I believe the peak limit at 1.8 MHz is 500 V/m. The equipment in my house is not affected (well just a little) with the application of a few ferrites and filters. The field in the adjacent neighbors homes is in the tens of volts/m. No complaints yet. Just remember, in words of N6SU if you can't see it it can't hurt you. Dave Cuthbert WX7G Micron Technology 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: davehe...@attbi.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
