Help finding Company
A friend in Europe is trying to obtain contact info on a company called "Air-Modem Inc". He thinks they are in Northern California. Does anyone know where there might be located? He has a contact name, Ashwin Mody?? Thanks, David Seabury This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: HF earth resistance test
Bob, I have used a method that will give the RF loss resistance of a particular ground system. The rod must be out in the open- away from buildings by a few meters or so. Mount a 1/4 wavelength vertical antenna (7 meter rod)at the grounding point. Measure the input impedance at resonance. The ground resistance is equal to the input R-36 ohms. For example, you measure 76 ohms and your ground rod RF resistance is 40 ohms. Dave Cuthbert Micron Technology From: bob.edwa...@invensys.com [mailto:bob.edwa...@invensys.com] Sent: Friday, October 10, 2003 4:04 AM To: emc-p...@majordomo.ieee.org Subject: HF earth resistance test I'm used to testing earth rod installations at LF or DC. Does anyone know of an established technique for assessment at HF, say around 10MHz? Our Technical Director had heard of it when he was out in the far east, but no other details. Regards, Bob Edwards, Product Compliance Technical Authority Westinghouse Rail Systems Ltd., Chippenham, Wilts, U.K. Tel: (0)1249-441544 Fax: (0)1249-441419 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: PSpice model for 1/4 wavelength antenna
Robert, sorry this is so late but I was out last week. A three-element series RLC SPICE model for your antenna is: 36 ohms, 2.13 pF, 63 nH. Here is how it compares to a NEC model of a 6.5 inch long, #12 AWG wire, over perfect ground: FREQ SPICE NEC 100 36-j668 1-j712 200 36-j294 5-j302 300 36-j130 14-j137 400 36-j2830-j27 500 36+j4859+j61 600 36-j113 123+j170 You can see that is looses accuracy above resonance. If you need a better model I think I can develop a better one that incorporates a transmission line. Dave Cuthbert Micron Technology From: robert Macy [mailto:m...@california.com] Sent: Wednesday, October 08, 2003 12:59 PM To: emc-p...@ieee.org Subject: PSpice model for 1/4 wavelength antenna Does someone out there have a PSpice model for a 1/4 wavelength antenna? 433.92MHz Something that I can change to reflect diameter of the rod, detuning, etc. Or, do you know someone who has such a model? Need it fast, please. - Robert - Robert A. Macy, PE .. m...@california.com 408 286 3985 . . . .. . . fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Heisenberg and signal measurements
Doug, a very timely article. I recently worked with somee others on this same issue. A short (1/4") probe extension caused serious overshoot/ringing on a Tektronix active probe. The solution was a series damping resistor but as you say, you cannot restore the lost bandwidth. SPICE clearly showed what was going on. Dave Cuthbert Micron Technology From: Doug Smith [mailto:d...@emcesd.com] Sent: Monday, October 06, 2003 5:42 PM To: emc-pstc Subject: Heisenberg and signal measurements This month's Technical Tidbit on my site (http://emcesd.com) has been posted (click on waveform graphic at the bottom of the home page). The abstract of the article is: Abstract: Heisenberg's Uncertainty Principle might be adapted in the context of signal measurements to say that one cannot measure a voltage at a node without affecting it. Simulation data is presented to show that under realistic conditions, active probes without damping resistors can significantly affect the signal to be measured. The result can be more serious than just signal loading. I have been increasing my lectures at Universities in recent years and will add another university here in the USA next spring. Although I lose income I could have made during the time spent, the effort does help the universities. My next continuing education lecture of this type is at Oxford University: my 2 day High Frequency Measurements and Noise in Electronic Circuits course in November. For details go to the Oxford site: http://www.conted.ox.ac.uk/cpd/electron cs/courses/high_frequency_measurements.asp Many airlines are running sales to the UK from the USA for as little as about US$200! It may be less expensive to fly from Denver to London than from Denver to Boston. And... Oxford is a great place to visit this time of year and attendance helps the University. Doug -- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Corrosion tests - NEBS or Milspec acceleration factors?
Gary, These were stainless steel wires inside protective polymer sheathing, extra thick multiple coatings. The wires were mounted on a "fence" and then placed under tension to make their resonance from wind, etc fairly high frequency - like the e string on a bass guitar. Seems the tension put so much internal stress into the wires and encouraged so much corrosion that the wires would only last a year, even 2 miles from an ocean. - Robert - On Fri, 10 Oct 2003 14:56:39 -0700 "GARY MCINTURFF" wrote: > Robert, > Thanks for the info. Do you mean stress from normal > nut/bolt torque or from a press-fit application. Here is > another small tidbit you might consider - a trick I got > from an aircraft mechanic. Even if the part is stainless > steel if you are working around it with non-stainless > tools you can compromise the stainless part with the > tool. It is the tool material that could be starting the > corrosion. In the particular instance I was discussing it > was stainless steel panels that were being sheared, and > the shear didn't have stainless "shoes" or whatever the > actually shearing components are. These shoes smeared > onto the stainless parts and viola corrosion. When they > put stainless shoes on the shear the problem disappeared. > This was a Boeing 747 crew chief so he certainly has > the experience to make him believable. Might want to > check your manufacturing plant just for grins. > Gary > - Original Message - > From: robert Macy > To: GARY MCINTURFF ; emc-p...@ieee.org > Sent: Friday, October 10, 2003 12:01 PM > Subject: Re: Corrosion tests - NEBS or Milspec > acceleration factors? > > > > Gary, > > From experience with security systems only "close" to > the > seashore (approx 2 miles away) it is best to *NEVER* > have > any of the metal parts under stress/tension, else the > corrosion rates are incredibly accelerated. > > The particular stainless steel part had been tested > real > time in worse environments with absolutely no > degradation > detectable. Yet, in the actual application under > mounting > stress the stainless steel part repeatably failed > within 1 > year even that far away from the ocean. > > - Robert - > > Robert A. Macy, PE .. m...@california.com > 408 286 3985 . . . .. . . fx 408 297 9121 > AJM International Electronics Consultants > 101 E San Fernando, Suite 402 > San Jose, CA 95112 > > > > On Fri, 10 Oct 2003 09:47:40 -0700 >"GARY MCINTURFF" wrote: > > Ernie, > > I know you received Naftali's email so I will > just > > clarify a little more. We test and pass the GR-487 > > outdoor enclosure requirements for the > telecommunications > > industry but I have a client who is non-telecom. > > Telecommunciations customers seem to accept the test, > > because past experience has shown in meets the > equipment > > and time needs (20 years). Non-Telecommunications > > customers not familiar with the tests kind of expect > some > > sort of acceleration factor for the hours under test > to > > demonstrate how long the equipment will work, rather > than > > a more or less pass fail salt fog test. He wants to > how > > long the equipment can withstand the elements at his > > coastal location. Is there any sort of acceleration > model > > used in the salt fog test, or the mixed gasses and > > hygroscopic tests? He is a little unhappy with my > > current response (understandably) that experience > shows > > the test satisfies the screening requirements or else > > they would have been changed long ago to something > that > > did meet the equipment and time requirements. > > Can you give me a little insight? > > Thanks > > Gary McInturff > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Balun of bi-conical antenna.
Hello Derek, Not only does the 3110B have a balun, but it has a well designed one. We originally used another Bicon, but switched to the 3110B several years ago and have been very pleased with the consistent measurements in various geometries (horizontal, vertical, different distances). We were led to this choice by comments in this forum. Hope this helps. Regards, Don Umbdenstock Sensormatic From: LEUNG YAT WAH DEREK [mailto:ywle...@vtc.edu.hk] Sent: Monday, October 13, 2003 12:44 AM To: emc-p...@majordomo.ieee.org Subject: Balun of bi-conical antenna. My existing configuration ( for education purpose) of radiated emission test is connect the EMCO bi-conical antenna, Model 3110B( 30M to 300MHz) antenna directly to the amplifier and then to the spectrum analyzer, I read some books it should include the Balun when feed into the antenna, is there anyone know where to buy or how to build the Balun, and any negative effect if without balun, thanks advance for any help. Derek Leung.
Senior Consultant Position
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RE: Balun of bi-conical antenna.
The ETS catalog confirms this antenna does in fact have a balun built in. Tom Donnelly Smiths Aerospace Actuation Systems tdonnelly@act-sys From: Luke Turnbull [mailto:luke.turnb...@trw.com] Sent: Monday, October 13, 2003 6:56 AM To: emc-p...@ieee.org; ywle...@vtc.edu.hk Subject: Re: Balun of bi-conical antenna. Any Commercially available Biconical Antenna should have a balun built in to the structure of the antenna. (Normally a block that the elements connect into). The output will be a 50ohm N-type or BNC and can be used with the usual 50ohm unbalanced cable. Luke Turnbull >>> LEUNG YAT WAH DEREK 10/13/03 05:44am >>> My existing configuration ( for education purpose) of radiated emission test is connect the EMCO bi-conical antenna, Model 3110B( 30M to 300MHz) antenna directly to the amplifier and then to the spectrum analyzer, I read some books it should include the Balun when feed into the antenna, is there anyone know where to buy or how to build the Balun, and any negative effect if without balun, thanks advance for any help. Derek Leung. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Test Standards for IDEN and UMTS Digital Cellular Telecommunicati ons Networks
Hi all, Does anyone know where I can find test standards for IDEN and UMTS Digital Cellular Telecommunications Networks? Any help will be appreciated. David Shidlowsky Technical Writer EMC Laboratory ITL (Product Testing) Ltd. Kfar Bin Nun Israel Tel: +972-8-9797799 Fax: +972-8-9797702 Email: dav...@itl.co.il http://www.itl.co.il http://www.i-spec.com This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender.
Re: Balun of bi-conical antenna.
Any Commercially available Biconical Antenna should have a balun built in to the structure of the antenna. (Normally a block that the elements connect into). The output will be a 50ohm N-type or BNC and can be used with the usual 50ohm unbalanced cable. Luke Turnbull >>> LEUNG YAT WAH DEREK 10/13/03 05:44am >>> My existing configuration ( for education purpose) of radiated emission test is connect the EMCO bi-conical antenna, Model 3110B( 30M to 300MHz) antenna directly to the amplifier and then to the spectrum analyzer, I read some books it should include the Balun when feed into the antenna, is there anyone know where to buy or how to build the Balun, and any negative effect if without balun, thanks advance for any help. Derek Leung. This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Balun of bi-conical antenna.
My existing configuration ( for education purpose) of radiated emission test is connect the EMCO bi-conical antenna, Model 3110B( 30M to 300MHz) antenna directly to the amplifier and then to the spectrum analyzer, I read some books it should include the Balun when feed into the antenna, is there anyone know where to buy or how to build the Balun, and any negative effect if without balun, thanks advance for any help. Derek Leung.
