http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- George, The scope of 61000-4-3 covers the frequency range of 80 to 1000 MHz (for now). Some product standards may extend the frequency range lower or higher, but the 1kHz modulation is a seperate issue. I believe there is talk about raising the upper frequency to 6GHz. A decent single-channel power meter to measure forward power, including a power sensor, should cost less than $6000 new, and there are deals on eBay all the time for under $1000. Gigatronics, Boonton, Agilent, Rohde and Schwarz. There are HP 436 and 437 power meters and sensors on eBay all the time. (Make sure the 436 has the GPIB option). Check the specs on the power sensors to make sure the frequency range and dynamic range meet your needs. I can't image needing a power sensor that measures down to -100 dBm (I don't even know if they exist). If you pick a directional coupler to match the dynamic range of the sensor, you should only need a 50dB range. -30dBm to +20dBm is common. Try to keep the sensor operating in the upper end of its dynamic range to improve speed and accuracy. As for the 1kHz modulation frequency, that is not something that you should have to constantly monitor during a test, but you should have some procedure to make sure you are not clipping at the peak of the modulation envelope. Most auditors will ask what you have done to check that. This can be done with a spectrum analyzer, or with a power meter and modulation sensor. Note that the spectrum analyzer frequency range does not have to go down to 1Khz, it only has to cover the frequency range of the RF signal. The spectrum analyzer can also be used to check the harmonic content from the amplifier. This test will require software to run. Before you purchase any equipment, check to make sure the software supports it. Do you already have software? Good luck.
George Bittar <[email protected]> wrote: http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Hi Ed, I considered using HP3580, bus as llong as the equipment is for an University EMC Lab, it is necessary to be a new one. Not too much expensive. I need the frequency power meter to measure selectivelly 1KHz AM modulated signal, as per IEC 61000-4-3. It should measure levels from -100dBm to around +10dBm. I searched for spectrum analyzers, but most of them starts its range at 9KHz. Those that operate at lower frequencies are much more expensive. I quoted Acterna PSM137 and wow..... $25 thousand dollars... too expensive! I will take a look at eBay as you said and see if I find something. If you have other things, please contact me...suggestions are always welcome.:-) Regards GEorge Price, Ed wrote: http://www.ieee-pses.org/symposium http://www.emc2004.org/ From: George Bittar [ mailto:[email protected]] Sent: Monday, August 09, 2004 9:43 AM To: [email protected] Subject: Selective Frequency Power Meter Dear Group, I am looking for a selective frequency power meter to use in immunity tests. It would be a plus if it has some serial, gpib or usb output to connect on PCs and download data etc. Does anyone know such equipment? I've been looking on the internet, but didn't find much... The frequency range should include 1KHz and go up to some MHz. regards, -- George Bittar EMC Test Engineer - VTS George: Is there some reason you can't or don't want to use a spectrum analyzer? That frequency range is within the capabilities of old HP-856x series analyzers, and they have full remote I/O via an IEE-488 bus. Or, you could use something like the old HP-3580 analyzer, which covers something like 20 Hz through 300 kHz, and then switch over to another analyzer to cover your higher range. You could also try using a good oscilloscope with a FFT capability for the low frequencies, and again switch to a SA for the higher frequencies. I see EMC-10's, EMC-25', NM-17/27's and NM37/57's on eBay all the time. All of these will support remote control and data I/O, although not in the convenient IEEE-488 style. You may have to implement your own computer interface, dealing with discrete logic lines, BCD clusters and analog DC ramps. (I have seen only one auction for a CCI-7, the computer interface for Eaton series 7 receivers and IEEE-488, and that didn't include the huge multi-line receiver cables.) Finally, in measuring immunity, you should need much selectivity in your meter; we would hope that spurious and harmonic content of your test signal would be -35 dBc or better. I would think you could use suitable directional couplers and a broadband power meter. You ARE trying to monitor forward power? If you are trying to monitor generated field strengths using a monitor antenna, or if you are trying to pre-calibrate your chamber for field uniformity, then there's other systems you should consider first. Maybe we can give you better advice if you better define your goals, resources and constraints. Regards, Ed Ed Price [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. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: Ron Pickard: [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.ieeecommunities.org/emc-pstc -- >George Bittar EMC Test Engineer - VTS DÍGITRO TECNOLOGIA E-mail: [email protected] Fone:(48) 281-7169 / (48) 281-7000 Fax:(48) 281-7299 Site: www.digitro.com.br <http://www.portaldigitro.com.br/> ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: Ron Pickard: [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.ieeecommunities.org/emc-pstc Bob Richards [email protected] http://www.toprudder.com ------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. IEEE PSES Main Website: http://www.ieee-pses.org/ To post a message send your e-mail to [email protected] Instructions for use of the list server: 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: Ron Pickard: [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.ieeecommunities.org/emc-pstc
