What is the purpose of the separation, anyway? Known effects of two close senders are cross-modulation and intermodulation, caused by the emission from one sender impinging on the non-linearity of the output stage of the other. But there is no way of specifying a distance (other than a trivial 100 miles!) which would prevent this in all cases. The magnitudes of the effects depend on the detailed designs of the senders' output stages and antennas. With best wishes DESIGN IT IN! OOO – Own Opinions Only <http://www.jmwa.demon.co.uk/> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England Sylvae in aeternum manent. From: Bill Stumpf [mailto:bstu...@dlsemc.com] Sent: Wednesday, February 15, 2017 7:28 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Co-located modules I don't have any conclusively documented evidence from the FCC. This supposition is taken from recent FCC presentations, current KDB's and conversations with trusted "co-inhabitants" in this industry. An example of this indication is provided below. It is from an April 2015 FCC TCB Council presentation regarding KDB 551693 DR01. Real purpose of no-collocation condition – Not to restrict device usage options – Instead is to require compliance of multi-radio simultaneous transmission operations within a single end product • In cases where that is not already evaluated in the applications, or • For use outside parameters/scope for which the device was already evaluated I know in the past we've referenced 20cm as the minimum distance between antennas at which the FCC considered two simultaneously transmitting transmitters to be collocated. Even that was unwritten though. It would be nice to have a more clearly defined answer to what is considered collocation for requiring FCC multi-transmitter product procedures. Perhaps I will submit a KDB inquiry to the FCC... Bill From: msherma...@comcast.net <mailto:msherma...@comcast.net> [mailto:msherma...@comcast.net] Sent: Wednesday, February 15, 2017 11:33 AM To: Bill Stumpf <bstu...@dlsemc.com <mailto:bstu...@dlsemc.com> > Cc: EMC-PSTC <EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] Co-located modules Bill -- This "in the same enclosure" interpretation sounds new and drastic to me. Do you have any official document/link on this interpretation? thanks Mike Sherman Graco Inc. _____
From: "Bill Stumpf" <bstu...@dlsemc.com <mailto:bstu...@dlsemc.com> > To: "EMC-PSTC" <EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> > Sent: Wednesday, February 15, 2017 7:34:19 AM Subject: Re: [PSES] Co-located modules The latest chatter I gathered on this topic is that the FCC considers collocated as "in the same enclosure". Indications are that any reference to <20cm being considered collocated has been set aside. Bill From: Michael Derby [mailto:micha...@acbcert.com] Sent: Wednesday, February 15, 2017 2:18 AM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] Co-located modules Hi Stephen, One thing to remember is that “must not be co-located” really just means “must not be co-located without some additional effort” For example, co-locating two modules and then calculating the new combined RF Exposure MPE value to verify that the product still meets the requirements, would be acceptable. It does not necessarily mean a C2PC is needed, for example. I think you’re right that 20 cm is ‘good guidance’ with regard to RF Exposure. But if your modules are 20.5cm apart, you might still want to consider the overall compliance of that final product… and a co-located MPE calculation is not too hard. Thanks, Michael. From: Stephen Whalen [mailto:scwha...@bellsouth.net] Sent: 14 February 2017 23:34 To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] Co-located modules All, For a module that has "must not be co-located" restriction on FCC grant. What is the minimum separation distance allowed for another transmitter? I recall 20cm but can't find where it is documented. Regards, Stephen - ---------------------------------------------------------------- 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 <emc-p...@ieee.org <mailto:emc-p...@ieee.org> > 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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.com> > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org <mailto:emc-p...@ieee.org> > 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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.com> > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org <mailto:emc-p...@ieee.org> > 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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.com> > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org <mailto:emc-p...@ieee.org> > 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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.com> > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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 <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>