Seen as much as 12 dB at test labs which have performed site testing with less than 0.5dB variation between them.
1.8dB was traced to spectral regions using conservative antenna factor table, and part [at least to my thinking] was caused by the choice of GND plane which interacts with the variations in radiator impedances of the the EUT. At least, frequencies from low impedance sources seemed to increase at one site while frequencies from high impedance sources seemed to decrease. [This was more a post observation than a concept rigorously pursued] "Charlie Blackham" <emcpstc@?sulisconsultants.?com> on Fri, October 29, 2010 12:04 am wrote: > Group > > > > Testing a product to CISPR11 class B and seeing quite a difference in > results below 1 GHz when tested at two different labs. > > > > I don't wish to discuss why this is being done, but would be very grateful > for any Quantitative data people have on differences between different > OATS > or between OATS and semi-anechoic or anechoic chambers. > > > > (The EUT is a small box with a single 2-core 24V dc/signal cable) > > > > Regards > > Charlie > > > > Charlie Blackham > > Sulis Consultants Ltd > > Tel: +44 (0)7946 624317 > > Web: <http://www.sulisconsultants.com/> www.sulisconsultants.com > > Registered in England and Wales, number 05466247 > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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 <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
