Dennis, Correct. In fact, the required notice on the product or in the manual explicitly states that your Part 15 device is not offered any protection against interference. Of course, it isn't supposed to cause any interference, either. The limits were designed to provide a reasonable level of protection against interference to radio services (and television is just radio with pictures). Protect your neighbor from you. Not you from yourself. And in this case the limits have been wildly successful. One could argue that the limits are overly conservative, but that's a fight I am not going to get involved in. I'm too old and will be long gone before that one would be remotely close to being resolved. :-)
Ghery S. Pettit -----Original Message----- From: Dward [mailto:[email protected]] Sent: Wednesday, June 04, 2014 10:23 AM To: [email protected] Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp I do not want to speak for Mike Violette, but what I think he is referring to by interference is the fact that, while the FCC could care less if two part 15 devices interfered with each other, they do care if part 15 devices interfere with licensed services. And it is in this area that the 'issue has been solved' by the 'amazingly conservative' class B limits. Dennis Ward Senior Certification Engineer PCTEST This communication and its attachments contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient (s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachment(s) are free from computer virus or other defect. Thank you. -----Original Message----- From: Richard Nute [mailto:[email protected]] Sent: Wednesday, June 04, 2014 10:02 AM To: [email protected] Subject: Re: [PSES] radiated emissions testing may understate actual emissions, an example using a class D stereo amp On 6/4/2014 9:47 AM, Mike Violette wrote: "Class B limits are amazingly conservative, to which large populations of devices ascribe." Try using an ordinary AM radio beside a compact fluorescent lamp as on a beside table. - ---------------------------------------------------------------- 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]>
