RE: EMSCAN (was TV nostalgia/EMI sniffer goggle)Hi George: You are most correct the earlier units did only have frequency coverage to 1.0Ghz, but the newer units go up to 2.7Ghz. Frank Krozel
Frank Krozel TEL: 630-924-1600 FAX: 630-924-1668 MOBILE: 630-258-5421 (24/7) TEL: 630-653-9090 Home Electronic Instrument Associates-Central, Inc. Serving the Midwest with Electrical Engineers Since 1971 Website: http://www.electronicinstrument.com 123 East Lake St. Suite 300 Bloomingdale, IL 60108 ----- Original Message ----- From: George Stults To: 'Ehler, Kyle' ; 'Ken Javor' ; emc-p...@majordomo.ieee.org Sent: Wednesday, August 08, 2001 8:09 AM Subject: RE: EMSCAN (was TV nostalgia/EMI sniffer goggle) I also looked at EMSCAN about 2 years ago. I seem to recall that it was limited to a little over 1GHz on the top end at that time. We didn't buy it, because we had harmonics above 1 GHz. -George -----Original Message----- From: Ehler, Kyle [mailto:keh...@lsil.com] Sent: Tuesday, August 07, 2001 12:24 PM To: 'Ken Javor'; emc-p...@majordomo.ieee.org Subject: RE: EMSCAN (was TV nostalgia/EMI sniffer goggle) I mini-evaluated an EMSCAN about 4 years ago. Cute tool! At the time, this little gem utilized a planar array of 1,024 microantennae, coupled to an RF processor and pc. The radiation display is a user-variable-interpolation color map (spectral or spatial), but a bit imprecise in X-Y location, and forget about the Z plane. You could see a circuit trace acting as an emitter, but you have to be diligent in comparing the pwb layout with the schematic and the tool's radiation profile report. It was also a bit slow. That might have changed since then. Here's a link: http://www.emscan.com/product/prodline.html I could not sell our pcb design engineers on the tool -not even for use as a prescanner. Now our mechanical folks are having a dickens of a time containing 2Gbps fibre channel harmonics after the pcb design is done. Thanks for the job security. <boneheads> The biggest problem with this weapon was the absolute need for close proximity and repeatable indexing. This severely affects the accuracy and repeatability of the results, making before/after comparisons questionable. For many of us, placing an operating pwb on a planar surface for scanning presents a major challenge. I dont know about you, but we have a backplane that the pwb plugs into, then of course there is cabling, power supplies and cooling to worry about. Not to mention the CRU canisters for each module. Then it needs to be functional. I witnessed differences in emission profile that were highly sensitive to operating modes of the firmware loops and application software. It is extremely difficult if not impossible to do an accurate comparison of a bare board to an assembled and completely functioning EUT. So you are forced to scan a bare board rather than a fully configured and functioning system. For our purposes (debugging the EMI containment) this was of no practicality. Back to sniffer loops and horns.. On the other hand, one of the proper ways to design for compliance is to design for containment of the emissions at the [board level] source. This is where the practicality of the EMSCAN comes into play. I found the tool's virtue for scanning the solder side of the board (close proximity) excellent, but for the component side (which is where most of the radiation sources and fixes would occur) the proximity was poor, grossly affecting the location and precision of the readings. btw I dont work for, or have any connection with, EMSCAN. kyle -----Original Message----- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, August 06, 2001 5:58 PM To: John Woodgate; emc-p...@majordomo.ieee.org Subject: Re: TV nostalgia You could use an array of very short dipoles or small loops and gain in resolution by giving up efficiency, meaning that the viewer would have to be near the source. Although I have no detailed knowledge of it, I expect this is the principle behind the devices upon which you lay an operating PCB and the device maps hot spots. But clearly you will never get optical or IR viewer resolutions. ---------- >From: John Woodgate <j...@jmwa.demon.co.uk> >To: emc-p...@majordomo.ieee.org >Subject: Re: TV nostalgia >Date: Mon, Aug 6, 2001, 12:28 PM > > > <95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com>, Ehler, Kyle > <keh...@lsil.com> inimitably wrote: >> Doug has touched on what I think would be a great tool for the >> EMI hunter...but rather than a 'sniffer', a 'goggle' similar >> to what Geordi wears that facilitates the direct viewing of EM radiation. >> >> Ideally, the device would allow adjustable band 'viewing' of the radiation >> frequency, intensity, polarity and propagation pattern(s). > > Yes, it sounds much more attractive than a sniffer, which would produce > BAD smells around some equipment. And it isn't technically unfeasible. > The problem is the poor resolution, even a microwave frequencies, due to > the wavelength of the emission. At 150 kHz, the wavelength is 2 km, so > only very BIG things are visible. > -- > Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk > This message and its contents are not confidential, privileged or protected > by law. Access is only authorised by the intended recipient - this means YOU! > The contents may be disclosed to, or used by, anyone and stored or copied in > any medium. If you are not the intended recipient, please advise the sender > yesterday at the latest. > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > http://www.rcic.com/ click on "Virtual Conference Hall," > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
