Thanks Joe. I remember the "harm portion" from years ago when modems might be two 4 or 6 inch X 12 inch deep boxes that were stacked upon each other. Difficult to set up and certainly not able to be placed into a card slot of your laptop (laptops not having yet been invented - and I see many of our readers looking up "dinosaur" to see if maybe I might be standing in the pictures background). This was also before the general application of part 15 to computers. So I had always divided the two parts for modems right along the lines of your second paragraph. I'll add the "out of band" item to what is left of my brain cells. Appreciate the excellent synopsis. Gary
From: Joe Randolph [mailto:[email protected]] Sent: Thursday, August 17, 2006 9:15 PM To: McInturff Gary; Price, Ed; [email protected] Subject: RE: FCC Part 68 On 8/17/2006, Gary McInturff wrote: >Doesn't part 68 have more to do with isolation and operation than >emissions? Doesn't one have to have both parts 15 and 68? Hi Gary: Among other things, Part 68 places limits on the "out of band" signal power that appears on the phone line. These limits extend out to 6 MHz. The limits are generally easy to meet but I have seen cases where a nearby DC/DC converter coupled into the phone line circuitry and caused the equipment to fail Part 68. You are correct that most equipment that is subject to Part 68 is typically subject to Part 15 as well. The focus of Part 68 is to protect the public phone network from harm and interference. The purpose of Part 15 is to protect other equipment from RF interference. Part 15 typically applies to any equipment that has a digital clock of 10 KHz or higher, while Part 68 applies only to equipment that connects to the public switched telephone network. Depending on the type of equipment, it can be subject to Part 15, Part 68, or both. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (USA) http://www.randolph-telecom.com - 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 ______________________________________________________________________
