Kevin Stir away old chap, it is Friday after all....
1) The antenna is preferred to be 3m from the EUT. You can use less. I use about 2.75m because my power amplifier hasn't got quite enough guts where the chamber sucks out a couple of frequencies. 2) Why 1m maximum? Annex B mentions that a log period antenna will typically have a depth if 1.5m. 3) Don't understand this comment. In a broadband antenna don't you have to take the thing as a "whole"? Clause 6.2 (calibration of field) states "The field sensor shall be at least 1m away from the field generating antenna. A distance of 3m between antenna and EUT is preferred. This dimension is taken from the centre of a biconical antenna or the tip of a log periodic antenna.". I have an EMCO biconilog antenna which has a line marked "RI" near the tip. This is where EMCO reckon you should measure your antenna to EUT distance from. For immunity, the EUT to antenna distance isn't that critical though. What is critical is that the distances when calibrating the field and EUT testing are as near as possible identical. Regards Chris > -----Original Message----- > From: Kevin Hight [SMTP:[email protected]] > Sent: 06 April 2001 16:04 > To: Colgan, Chris; 'Emc-Pstc' (E-mail) > Subject: RE: IEC 61000-4-3 > > Chris, > > Allow me to stir the pot a little. > > 1) The antenna is to be 3-meters from the calibrated field. > 2) The antenna may be as long a 1-meter, front-to-back. > 3) The worst performing section of the antenna is the furthest section > away. > > If you move your antenna 1-meter closer, such that the back of the antenna > is 3-meters away, are you violating the standard? > If you move your antenna 1-meter back, such that the front of the antenna > is > 3-meters away, your are adding significant cost to your test setup due to > the additional power requirement. > Is a middle ground the most acceptable, 2.5-meters from the front of the > antenna and 3.5-meters from the back of the antenna, both from a > manufacturers cost and from the standards requirements. > > > Regards, > ____________________________________ > Kevin J. Hight - Principal Compliance Engineer > Colorado MEDtech, Inc. > 6175 Longbow Drive, Boulder, Colorado 80301 > Phone: (303) 530-8288 x-3111 Fax: (303) 581-1003 > Email: [email protected] http://www.cmed.com > > "Man's mind once stretched by a new idea, never regains its original > dimension." > -- Oliver Wendell Holmes > > > > -----Original Message----- > > From: Colgan, Chris [SMTP:[email protected]] > > Sent: Friday, April 06, 2001 2:34 AM > > To: 'Emc-Pstc' (E-mail) > > Subject: RE: IEC 61000-4-3 > > > > > > The calibrated uniform field is a 1.5m square vertical plane 0.8m above > > your > > ground plane and 3m from your antenna, usually the tip (the size of the > > vertical plane and the antenna distance can be smaller but that's not > the > > issue here). The EUT is placed so that the panel you are testing is > > illuminated by the vertical field ie the part of the EUT nearest to the > > antenna should always be 3m away. I know this sounds rude and I don't > > mean > > it to be but if you weren't sure that the uniform field was a vertical > > plane, how did you calibrate it? > > > > Regards > > > > Chris Colgan > > Compliance Engineer > > TAG McLaren Audio Ltd > > The Summit, Latham Road > > Huntingdon, Cambs, PE29 6ZU > > *Tel: +44 (0)1480 415 627 > > *Fax: +44 (0)1480 52159 > > * Mailto:[email protected] > > * http://www.tagmclarenaudio.com > > > > > > > -----Original Message----- > > > From: [email protected] > > [SMTP:[email protected]] > > > Sent: 05 April 2001 23:24 > > > To: [email protected] > > > Subject: IEC 61000-4-3 > > > > > > > > > Collogues, > > > > > > In this specification, is it stated anywhere if the unity field is a > > > volume ( 1 cubic meter) or is it a plane location (the calibration > > plane)? > > > > > > I'm having questions raised about rotating the EUT (in 90 degree > > > increments) > > > (which now has us over testing the EUT because it is closer to the > > antenna > > > by 0.3m at the 90 degree point) or under testing when tested at 270 > > > degrees? > > > I thought I had read somewhere that the unity field was the 1 cubic > > meter > > > box at the (80cm) table top centered and aligned with the calibration > > > plane? > > > > > > > Michael Sundstrom > > > > Product Test Technician EMC > > > > Nokia Mobile Phones, Dallas PCC > > > > > > > > * Email [email protected] > > > > % Desk (972) 374-1462 > > > > *Mobile (817) 917-5021 > > > > * Fax (972) 374-0901 > > > amateur call: KB5UKT > > > > > > > > > ------------------------------------------- > > > 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: > > > [email protected] > > > with the single line: > > > unsubscribe emc-pstc > > > > > > For help, send mail to the list administrators: > > > Michael Garretson: [email protected] > > > Dave Heald [email protected] > > > > > > For policy questions, send mail to: > > > Richard Nute: [email protected] > > > Jim Bacher: [email protected] > > > > > > All emc-pstc postings are archived and searchable on the web at: > > > http://www.rcic.com/ click on "Virtual Conference Hall," > > > > > > ************************************************************** > > 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. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > [email protected] > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Michael Garretson: [email protected] > > Dave Heald [email protected] > > > > For policy questions, send mail to: > > Richard Nute: [email protected] > > Jim Bacher: [email protected] > > > > All emc-pstc postings are archived and searchable on the web at: > > http://www.rcic.com/ click on "Virtual Conference Hall," ************************************************************** 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. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
