I remember working on such a filter a few years ago and from what I remember there were no isolation type components - it was more of a high pass/low pass filter rather than an isolation type device. This is just my memory though, so I could be wrong.
If you think about it though, there is really not much need for an isolation type device within such a filter (& it would add cost) ...and the loss from an isolation component would further effect the already critical distance requirements for DSL, so I doubt that these filters would have an isolation component. Dave -----Original Message----- From: Roman, Dan [mailto:dan.ro...@intel.com] Sent: Wednesday, September 18, 2002 8:56 AM To: 'Peter Merguerian'; 'Rob Keller'; emc-p...@majordomo.ieee.org Subject: RE: DSL Modems All, When Verizon installed my ADSL service a couple years back they put in what they called a whole house filter, but it is actually a splitter/filter. I don't recall any Listing marks of any kind on the device. It was installed on the network side of the gray box on the side of my house, not on the customer premise side so Listing may not apply. I took the device with me when I moved but DSL was not available in my new location. It is potted so I have no hope of determining the construction, guess I could apply ring voltage to it in the lab and hi-pot it and see what happens! I suspect though that it is TNV-3 in and TNV-3 out. Shortly after my DSL was installed (I was one of the first in my area) they stopped installing the whole house splitter and required the user to put a filter on every phone (yuk) except for the DSL modem. So even if splitters are available that do a TNV-3 to TNV-1 or even TNV-3 to SELV connection, at least in the Verizon NJ customer area DSL modems are TNV-3 all the time. Dan -----Original Message----- From: Peter Merguerian [mailto:pmerguer...@itl.co.il] Sent: Wednesday, September 18, 2002 9:24 AM To: 'Rob Keller'; emc-p...@majordomo.ieee.org Subject: RE: DSL Modems Rob Hi! I assume that the "ADSL" modem is connected to the phone line through an external splitter. If you find an approved splitter having the required TNV-3 to TNV-1 insulation, and you specify the specific splitter in your manual, I gather that your interface can be TNV-1. If no such splitter is specified, then the interface should be classified TNV-3. Now a question to the group - is anyone familiar with external Listed/Certified splitters that have the TNV-3 - TNV-1 insulation? This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 http://www.itl.co.il http://www.i-spec.com -----Original Message----- From: Rob Keller [mailto:r...@cclab.com] Sent: Tuesday, September 17, 2002 10:38 PM To: emc-p...@majordomo.ieee.org Subject: DSL Modems Greetings all, Question regarding the classification of DSL modems. DSL modems connect to the standard telecom network yet they do not require a ring signal or go on/off hook, therefore the classification would be TNV-1. Yet there are ring signals still present on the telecom lines for the the other equipment. So, because of the ring signals, which would exceed the limits of SELV, connecting to the input the modem, should the classification be TNV-3. Any insight would be greatly appreciated. Rob Keller Product Safety Engineer Communication Certification Laboratory r...@cclab.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"