As I noted in the previous post, I don't know very much about BPL. I surmise that the home electrical mains serve as a transmission line for the BPL signal. However, whereas the home mains system distributes mains power (50/60 Hz) differentially, I assume that the BPL signal is sent over the entire mains wiring (phase/neutral/safety ground) in a common mode fashion. In order for that to happen, there has to be some kind of interface between the sending/receiving device and the power lines that acts as a matching network and mains power frequency blocker. From the PC or other device accessing the internet via BPL to this matching/blocking device, the radiation should be contained via whatever packaging and wiring is used (Ethernet/USB/whatever). In other words, the matching/blocking device is just one more peripheral attached to the host PC for radiated emission testing on an OATS. For that kind of testing, the mains side could be simulated in some shielded fashion as strictly support equipment. But from the BPL side of the matching/blocking device onwards, that is where the radiation will occur that is easier to control and measure as an rf current. And this is the radiation that has everyone in the amateur community all excited, because it has the capacity to radiate efficiently from the long lines associated with low voltage mains wiring.
> From: John Woodgate <[email protected]> > Date: Tue, 8 Aug 2006 06:06:17 +0100 > To: [email protected] > Subject: Re: Near field/Far field what is D. > > In message <c0fd3eda.411bd%[email protected]>, dated Mon, 7 > Aug 2006, Ken Javor <[email protected]> writes > >> Now you could certainly idealize the transmission line for the >> purposes of a standard test, and you would need to, but if you do that, >> why not specify and measure the BPL current on that matched >> transmission line? > > Would you please clarify what you mean by 'transmission line' in this > context? Is it the transmission line between the BPL sender and the > mains network? > > I ask because I am involved in a similar issue; measuring the emissions > form audio-frequency induction loops fed by Class D amplifiers. At > present, measuring the current in one conductor of the cable between the > amplifier and the loop is believed to be the first possibility to be > investigated. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > 2006 is YMMVI- Your mileage may vary immensely. > > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > 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] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
