Interesting thought, Bill. That ought to make a very nice series of harmonics!
My favorite, and more controllable method is to use an RF generator capable of producing +15 to +20 dBm output, which I then connect to a small H-field loop. That way, I can control where the field is introduced into the product and can usually narrow down the sensitive node. I recently measured 1 to 3 V/m at the probe tip, depending on the frequency. Also, this method won't cause interference to existing services - something the FCC frowns upon. :-) However, I hate to drag the generator around to client sites all the time. What I've been looking for is a USB-controlled brick, similar to what Mini Circuits sells, that can tune at least 80 to 1000 MHz and has AM modulation capability. Maybe someone on the list knows of something that would work? Cheers, Ken Kenneth Wyatt Wyatt Technical Services LLC Woodland Park, CO [email protected] www.emc-seminars.com (Sent from my iPad) On Mar 27, 2013, at 7:50 PM, Bill Owsley <[email protected]> wrote: > For cheap and easy, I'd suggest a VCO in the range of a divisor of around 900 > MHz, and feed that into a really fast technology buffer or driver good to a > couple of GHz., which then drives a trace without any impedance control to a > variable termination that can be adjusted from short to open, to make voltage > and current emissions broadcasting on all harmonics for your listening > enjoyment. > Depending on how you create your antenna, you can torture your device in many > different ways. > > > > From: Ken Wyatt <[email protected]> > To: "Paasche, Dieter" <[email protected]> > Cc: "[email protected]" <[email protected]> > Sent: Wednesday, March 27, 2013 2:42 PM > Subject: Re: [PSES] March EMC blog postings > > Good question, Dieter, > > I use a TriSquare frequency hopping (license free) radio to produce 900 MHz > emissions for radiated immunity. More info and where to purchase may be found > here: www.trisquare.us > > They don't work well as radios, but they put out about a half watt, or so, at > 915 MHz. > > You might also check out my blog postings on immunity testing on > www.tmworld.com (The EMC Blog) for more ways to produce RF for immunity > testing. > > Cheers, Ken > > Kenneth Wyatt > Wyatt Technical Services LLC > Woodland Park, CO > [email protected] > www.emc-seminars.com > (Sent from my iPad) > > On Mar 27, 2013, at 11:30 AM, "Paasche, Dieter" > <[email protected]> wrote: > >> Hi Ken, >> >> By the way, what do you do for radiated immunity if you do not have a lab? I >> normally try to use some radiators around here, like WIFi router, walkie >> talkies, etc, but according to a test lab I have a problem around 900 MHz. >> Is there are cheap practical way to simulate that signal? >> >> Sincerely, >> >> Dieter Paasche x7211 >> >> From: Ken Wyatt [mailto:[email protected]] >> Sent: March 27, 2013 12:56 PM >> To: Paasche, Dieter >> Cc: [email protected] >> Subject: Re: [PSES] March EMC blog postings >> >> Ahh, you got the joke! Thanks for the additional thoughts. >> >> Cheers, Ken >> >> Kenneth Wyatt >> Wyatt Technical Services LLC >> Woodland Park, CO >> [email protected] >> www.emc-seminars.com >> (Sent from my iPad) >> >> On Mar 27, 2013, at 10:05 AM, "Paasche, Dieter" >> <[email protected]> wrote: >> Hi Ken, >> >> Analyzing the picture under your EMC troubleshooting parts storage >> >> I saw something extremely useful and practical. The First aid kit side by >> side to the cupper tape! J Brings up many (painful) memories. >> >> By the way, we are using a different Nickel conductive tapes now from >> Schlegel, which I found are very good as well. Not as good as copper, but >> good enough to find the problem. Besides it is less expensive, more flexible >> and less cutting fingers. >> >> >> Sincerely, >> >> Dieter Paasche x7211 >> >> From: Ken Wyatt [mailto:[email protected]] >> Sent: March 27, 2013 11:34 AM >> To: [email protected] >> Subject: [PSES] March EMC blog postings >> >> Hi All, here's a recap of my blog postings this month. >> >> Review: Amazing USB 5.35 GHz spectrum analyzer >> (http://www.tmworld.com/electronics-blogs/the-emc-blog/4410523/Review--Amazing-USB-5-35-GHz-spectrum-analyzer) >> >> Always on the lookout for useful, but inexpensive test equipment, I recently >> ran across the Triarchy Technologies USB spectrum analyzer, model TSA5G35. >> The one thing that really struck me was the whole thing was built into a USB >> dongle, just a little larger than a memory stick. What's more, the >> advertised frequency range was 1 MHz to 5.35 GHz. This, I had to see for >> myself. >> >> EMC troubleshooting parts storage >> (http://www.tmworld.com/electronics-blogs/the-emc-blog/4408438/EMC-troubleshooting-parts-storage) >> >> For those of you who regularly troubleshoot EMC issues, wouldn't it be >> convenient to have all your "fix-it" parts all in one place? >> >> Milwaukee EMC symposium >> (http://design-4-emc.com/2013/03/23/milwaukee-emc-mini-symposium-march-2013/) >> >> I was honored to be the featured speaker at the 13th annual EMC Society >> Chapter of the IEEE Milwaukee Section “EMC Mini-Symposium” this last March >> 19th. Hosted and managed by EMC engineer Jim Blaha (GE Medical), this was >> actually no mini-symposium – but is the largest regional gathering of EMC >> engineers in the country. There were a record 180 engineers from around the >> area, as well as a record 42 vendors showing their wares (with pictures). >> >> Protecting low-cost products from ESD >> (http://www.theconnectingedge.com/author.asp?section_id=2600&doc_id=259511) >> >> The best protection from ESD is a fully-shielded enclosure with all I/O and >> power connectors well-bonded to the enclosure. Many low-cost products, >> however, lack shielded enclosures because of cost. That creates a problem in >> protecting the circuitry from ESD. >> >> Bond those connectors, save your day >> (http://www.theconnectingedge.com/author.asp?section_id=2600&doc_id=260359&;) >> >> The No. 1 radiated emission issue -- and the one that frankly keeps me in >> business -- is poor cable shield terminations (bonding) to product >> enclosures. It's such a simple problem to solve, but lack of knowledge by >> designers is largely to blame. >> >> Hope your week is going well! >> >> Ken >> _______________________ >> Kenneth Wyatt >> Wyatt Technical Services LLC >> Woodland Park, CO >> Email Me! | Web Site | Blog >> The EMC Blog (T&M World) >> Subscribe to Newsletter >> Connect with me on LinkedIn >> >> - >> ---------------------------------------------------------------- >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to >> <[email protected]> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> Attachments are not permitted but the IEEE PSES Online Communities site at >> http://product-compliance.oc.ieee.org/ can be used for graphics (in >> well-used formats), large files, etc. >> Website: http://www.ieee-pses.org/ >> 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]> > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > Website: http://www.ieee-pses.org/ > 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]> > > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > 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]> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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]>
