I was wondering the same regarding “capacitor hold-up” keeping the magnetron working for up to a half sine.
As for the radio astronomy frequency allocations, here is the internationally recognized list: http://www.astrosurf.com/luxorion/radioastro-frequencieslist.htm <http://www.ukaranet.org.uk/basics/frequency_allocation.htm> Note that there is a band from 2655 to 2690 MHz and another from 2690 to 2700 MHz. Microwave ovens operate nominally at 2.45 GHz. However if you actually look at the spectrum when the oven is on, you’ll observe it uses much (maybe more?) of the 2.4 to 2.5 GHz ISM band. Conceivably, the signals could slop over to the nearest astronomy band. You’ll see this on the last page of my article on wireless interference: http://www.edn.com/electronics-blogs/the-emc-blog/4438663/3/Wi-Fi-network-interference--analysis--and-optimization <http://www.edn.com/electronics-blogs/the-emc-blog/4438663/3/Wi-Fi-network-interference--analysis--and-optimization> The real time spectrum analyzer used (Tek RSA306) only had a RT bandwidth of 40 MHz, so much of the signal lies "off the chart”. It’s interesting to note that the frozen capture of the instantaneous signal (orange line) clearly shows the pulsed 16 ms periodicity of the half-wave rectifier in the magnetron power supply. Ken _______________________ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! <mailto:[email protected]> | Web Site <http://www.emc-seminars.com/> | Blog <http://design-4-emc.com/> The EMC Blog (EDN) <http://www.edn.com/blog/The-EMC-Blog> Subscribe to Newsletter <http://www.emc-seminars.com/Newsletter/Newsletter.html> Connect with me on LinkedIn <http://www.linkedin.com/in/kennethwyatt> > On May 15, 2015, at 4:09 PM, Ed Price <[email protected]> wrote: > > Interestingly, many news sources quote the oven emission as “1.4 GHz” which > is very unlikely for a consumer oven. They didn’t mention if the telescope > was being used in the 2.4 GHz band (again unlikely), so I wonder if the > telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, > if the oven harmonics were to blame or if the telescope data-processing > equipment was actually the victim. One story at least admitted that > researchers were suspicious of the signals, as they only were a problem > during “working hours.” - ---------------------------------------------------------------- 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://www.ieee-pses.org/list.html (including how to unsubscribe) 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]>
