Dear Edward, I have to agree with you. Due to the antenna port measurement, I didn't question the length of the power wires (about 1.5 meters). It was our engineer who provided me with 1-foot wires to try. The only possibility is due to the setup. The transmitter was soldered to a test board (accessing test commands and power) which has a lot of noisy circuits (for other purposes). We have to switch to a blank test board. Power is through two pins to the test board. Somehow the noise finds its way to get into the transmitter. Best regards, Grace
On 7/1/08, Price, Edward <[email protected]> wrote: ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Grace Lin Sent: Friday, June 27, 2008 7:01 AM To: [email protected] Subject: Re: Power Spectral Density Measurement Dear Members, Thank you very much to those whe have commented. FYI. We found out the data discrepancy was caused by a test fixture/board (support test commands to set up channels and power level) and the length of power lead (from EUT to DC power supply). Best regards, Grace It's a bit difficult to understand how the length of the power cable affected the transmitter coaxial output port power spectral density? Ed Price [email protected] <mailto:[email protected]> WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (FAX) Military & Avionics EMC Is Our Specialty - ---------------------------------------------------------------- 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/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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- 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/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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
