>-----Original Message----- >From: richwo...@tycoint.com [ mailto:richwo...@tycoint.com] >Sent: Wednesday, July 02, 2003 5:43 AM >To: emc-p...@majordomo.ieee.org >Subject: CISPR Receiver/SA > > > >If you were purchasing a brand new, fully CISPR compliant EMC >receiver/SA, >and wanted to obtain the best value at the lowest cost, what would you >choose and why? Likewise, if you decided to purchase a used >receiver/SA, >what would you choose and why? > >Richard Woods >Sensormatic Electronics >Tyco International
Rich: I'd like to address the second half of your question, the lowest cost end. I wanted to have some kind of backup, a sanity check, for my fancy automated spectrum analyzer system. My solution was to buy old receivers on eBay. One particular system, the Eaton / Singer / Stoddart Series 7 receivers (NM-17/27 & NM-37/57) can be used with the CCA-7 quasi-peak adapter, to give you a very nice back-up or pre-compliance measurement capability. You can run these in manual mode, or use internal sweeps with an external plotter. And the amazing thing is that you can get these for $200 or so off of eBay. (The usual disclaimers; don't buy what you can't fix; the operator has to be smarter than the machine; do you feel lucky?) My experience was; bought an NM-17 for $160, works perfectly; bought an NM-37 for $65, bad tuning voltage, took a few hours to fix it; bought a CCA-7 for $110, works perfectly; bought an NM-7 for $125, works but cal control is noisy; bought an NM-65 for $175, has a power supply problem but haven't had time to look at it. So, using your criteria of lowest cost (and I think the value is there too, since it does the job), I spent about $650, and got a measurement system that covers 30 Hz to 12 GHz (OK, the 1-12 GHz part isn't working yet), with a QP capability too! Another low-end solution is an HP-141T spectrum analyzer mainframe, with 8552 IF and 8555 & 8553 plug-ins. This will give you 10 kHz to 18 GHz coverage, but only with a Peak detector. Get an 8556 plug-in, and you can extend the range down to 30 Hz. I have a complete 141 system, but can't really suggest it too strongly, since the surplus units are all over the range in quality. Buying one of these is depending on luck a bit too much for even me. They are still repairable by humans, but it helps to have very small fingers and lots of patience. BTW, one other thing that's often overlooked in the total cost is the fact that you don't have to maintain any periodic calibration on these back-up systems. (My company operates with an internal Metrology department, and every piece of equipment I have has to have a calibration budget, or be declared non-calibrated support equipment. Some very reliable instruments may have been written off long ago, but their calibration budgets remain. I have to be careful that, when I acquire something, I also consider the ongoing calibration cost too.) Obviously, the above are not economically competitive systems for a full-time test lab. OTOH, it's a big improvement over an oscilloscope with a loop probe antenna, or waving a hand-held scanner over your product. Regards, Ed Ed Price ed.pr...@cubic.com WB6WSN NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty
