Brent, The power cord is dressed casual. Sorry.
Class II construction - no ground wire, hence no ground plane to reference. Back at the office and am now viewing similar dissimilar results from two indoor and two outdoor sites, so it probably has something to do with the H-field, and the power cord radiator makes a little more sense to me, I think... Brian > -----Original Message----- > From: Brent G DeWitt > Sent: Saturday, February 12, 2011 3:53 PM > To: [email protected] > Subject: RE: [PSES] OATS vs anechoic > > > Hi again Brian, > > How is the power cord dressed and terminated at the ground > plane? Huge > variations between test sites on how this is done! > > Brent > > > -----Original Message----- > > From: Brian O'Connell [mailto:[email protected]] > > Sent: Saturday, February 12, 2011 6:22 PM > > To: [email protected] > > Subject: Re: [PSES] OATS vs anechoic > > > > Just finished 2d OATS site - was not able to detect much > of anything. > > > > Went back to indoors fully anechoic, where the noise plot > is deafening. > > > > This is a simple 100W unit with one main ac/dc converter and (6) dc > > current modulators. Construction is mostly plastic, with > exception of > > metal base plate. As it is Class II construction, there is > no ground > > wire. > > > > Bad stuff is at 40-80MHz and 200-500MHz. Did some isolation > > troubleshooting - looks like the input power cord is the > main radiator. > > > > The EMC engineers at all three sites are both baffled and > fascinated > > and want a sample unit to play with. I am very happy that they are > > amused, but I have to ship a product and cannot afford to > support the > > Southern California EMC industry. > > > > thanks, > > Brian > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]]On > Behalf Of Brian > > > O'Connell > > > Sent: Saturday, February 12, 2011 12:25 PM > > > To: [email protected] > > > Subject: OATS vs anechoic > > > > > > > > > Good People, > > > > > > Have tested at several sites. All are 'big' names and have a > > > good reputation. > > > > > > The 10m fully anechoic chamber data indicates from +5dB to > > > +11dB in several frequencies; while the 10m OATS says the > > > unit passes Class B, min -4.2dB. > > > > > > Huh?!? What is the physics behind the difference between an > > > outside site and absorbers? Where are the Borg when you > need them? > > > > > > Brian - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
