Gerald, Thanks for the speedy response. We do have an enclosure for our product but it is made of PC so it doesn't help much with EMC. The test lab also tried "painting" it with this conductive paint but it didn't help enough. I'll take up your offer and take this offline and contact you directly.
Thanks, Jon On Tuesday, 3 March 2015 19:05:56 UTC-5, Gerald wrote: > > A lot depends on SW as well. Best way to pass is to put it in a box, but > thee are some other things you can try that involve $$. > > You can contact me directly and we can have a lively discussion about your > issues. > > Gerald > > > On Tue, Mar 3, 2015 at 1:24 PM, Jonathan Mash <jon...@gmail.com > <javascript:>> wrote: > >> Good Afternoon, >> >> First off, thanks to the BB community for making this such a great >> resource for those working on the BBB and other boards. I have personally >> spent hours on this forum. >> >> I am hoping that someone monitoring this group may be able to help me and >> my company solve an EMC problem that we are facing the the BBB. *We are >> open to paid consultations to aid in solving this issue (Gerald?)*. We >> are building a product around the BBB that needs to pass FCC part 15 Class >> B. We are having trouble passing the tests mostly around the 625 MHz range. >> We were only 1-2dB above the limit in one lab and almost 10dB over at >> another lab (yes, test equipment makes a big difference!). We tried it with >> and without our custom shield attached. >> >> There is another thread here: >> https://groups.google.com/forum/#!searchin/beagleboard/625/beagleboard/Y6BhtzKx2oY/YQ_xjmmkWusJ >> >> that seems to have the same problem. That thread seems to have lost >> attention of the key players in this group so I thought I would create >> another thread to bring more attention to this critical issue. >> >> We have done some pretty aggressive modifications to the board and the >> only way we can get the board to pass is by completely disabling (and >> depowering) the LAN PHY. This was accomplished by removing FB4 and mangling >> part of the device tree so we don't get a kernel panic on startup. Not an >> elegant solution, I know. >> >> As suggested in the other similar thread, we tried shorting R136 but it >> actually made the noise worse. >> >> We also tried disabling (removing Y4) the McASP oscillator as that was >> also generating quite a bit of noise. Didn't help enough. >> >> Has anyone other than CircuitCo been able to successfully pass FCC with >> the BBBw/Ethernet enabled as part of a system? CircuitCo was probably able >> to pass because they could isolate the BBB with big filters on all cables >> because they aren't selling the BBB as as system but as a component. >> Because ours is a "Commercial System", we need to test with all cables as >> they would be typically installed. No giant chokes for us. >> >> Thoughts? Comments? Suggestions? >> >> Thanks! >> >> Jon >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to beagleboard...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Gerald > > ger...@beagleboard.org <javascript:> > http://beagleboard.org/ > http://circuitco.com/support/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
