Geetha Balasubramanian <[email protected]> wrote (in <[email protected]>) about 'Radiated Emission Testing', on Tue, 22 Mar 2005:
> There are 2 clock sources in the device, one runs at 12 MHz and the >other runs at 4 MHz. Frequencies showing up in the US lab report are >atleast the harmonics of these 2 frequencies. But frequencies mentioned >in the Taiwan lab report are looking funny (111.27, 135.3, 285.69 MHz. >etc.) That does look odd. I wonder if they left the door open! > US lab tested in OATS but the TAIWAN lab tested in a >anechoic chamber. I heard that chambers are not the correct way to >measure ( always the results will be wrong) that is why FCC never >accepts chamber measurement. Is it so? It's a very difficult issue indeed. I wouldn't advise you to pursue that. I really feel that you should simply accept the report and supply the USB cable with a ferrite. The alternative would be to go to Taiwan with a new sample, measured in USA and shown to pass, and measure it again in Taiwan. The cost of that would pay for thousands of USB leads, and your test results in USA do not encourage confidence that you would be able to convince the Taiwanese authorities to pass the product. -- Regards, John Woodgate, OOO - Own Opinions Only. There are two sides to every question, except 'What is a Moebius strip?' http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/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: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
