Hi Everyone, Thanks for your replies so far, it’s been really helpful. I had to return the design for a short while, when I get it back I now have a roadmap of things to do…
Again, thanks everyone! Derek. > On Nov 28, 2020, at 5:41 AM, James Pawson (U3C) <[email protected]> > wrote: > > Derek, > > I agree with Amund. Narrowband 240MHz (high speed mode clock rate) and 480MHz > (second harmonics from low differential pair matching) are classic USB > emissions. There may be a little something at 960MHz of 1.44GHz as well. > > I've had good results from RasPi boards in the past with USB so my immediate > line of inquiry would be any other USB devices in the test setup, followed by > the cables. > > Happy hunting! > James > > > James Pawson > The EMC Problem Solver > > Unit 3 Compliance Ltd > EMC Testing / Design for EMC / Problem Solving / Pre Compliance / Consultancy > / Environmental & Vibration > > www.unit3compliance.co.uk // 07811 139957 > 2 Wellington Business Park, New Lane, Bradford, BD4 8AL > Registered in England and Wales # 10574298 > > -----Original Message----- > From: Amund Westin <[email protected]> > Sent: 28 November 2020 09:43 > To: [email protected] > Subject: [PSES] SV: [PSES] Thoughts on what may be the emission source > > Derek, > > 240/480MHz sound like USB 2.0 High speed .... It's 4 USB-ports on the RPi ? > > Br > Amund > > > -----Opprinnelig melding----- > Fra: DEREK WALTON > Sendt: 28. november 2020 00:49 > Til: [email protected] > Emne: [PSES] Thoughts on what may be the emission source > > Hi Folks, > > I’m working on a product containing a Raspberry PI as the main controller. I > see two very strong emissions at about 240 MHz and 480 MHz. They are > obviously related. > > I’ve discounted video, but not having any details on the board it’s making it > hard to pin down the source. Anybody make some suggestions as to what the > source may be? > > Thanks, > > Derek. > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> > > - > ---------------------------------------------------------------- > 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]> - ---------------------------------------------------------------- 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]>
