http://www.ieee-pses.org/symposium http://www.emc2004.org/ --------------------------------------------------
Actually, I am not trying to measure de carrier, but the 1KHz modulated AM at 80% signal! So, I have to measure selectively the 1KHz signal at the terminals of the equipment in order to know if the equipment is DEMODULATING the signal. The power level of 1KHz signal cannot be higher than -40dBm for my application. I have to mesure the behavior of this signal and trace it against the carrier, which goes from 150KHz to 80MHz for 61000-4-6 and 80MHz to 1GHz;1.4GHz to 2GHz for -4-3, and I'm sure you all know that! :-) Is it clear now? The point is not the signal I am generating, but the signal I am demodulating. Regards George Brent DeWitt wrote: http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- George, Now that you've specified the application, why do you feel you need a frequency selective power meter? If you are monitoring forward power levels for a 61000-4-3 test system, then the meter can be totally broadband in the frequency range of 80 MHz to 1 GHz. Of course it's important to check that the final power amplifier isn't clipping and producing strong harmonics, but this can usually be estimated from the amplifier specifications. From my experience doing this test, it's really unnecessary to have a 110dB dynamic range. Something closer to 40-50 dB dynamic range, when paired with appropriate pads and directional couplers should do the trick. With respect, Brent G DeWitt (unemployed EMC engineer looking for a job) Loveland, CO From: [email protected] [ mailto:[email protected]]On Behalf Of George Bittar Sent: Monday, August 09, 2004 3:15 PM To: Price, Ed; [email protected] Subject: Re: Selective Frequency Power Meter http://www.ieee-pses.org/symposium http://www.emc2004.org/ -------------------------------------------------- Hi Ed, I considered using HP3580, bus as long 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 ------------------------------------------- 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 Engenheiro de Testes - 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
