Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: "Dennis G. Rears (FSAC)" Newsgroups: comp.dcom.telecom Subject: Basic Questions About Telephones Message-ID: <10692@accuvax.nwu.edu> Date: 10 Aug 90 18:20:54 GMT Sender: news@accuvax.nwu.edu Organization: TELECOM Digest Lines: 44 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 557, Message 8 of 9 I just had a second line installed in my house. I had to do some of the wiring which is now finished. I do have some basic questions that came out of it though: It seems as if each telephone cable contains four wires (red, green, black, and yellow). For one line only the red and green wires are used. The black and yellow wires are only used for the second line. If only one line is installed in a jack why do the yellow and black wires have to be attached? I suspect it doesn't. The modular jack that goes into the phone has four wires in it. Why is that, if only the red and green are required for service? Just in case you have a two line phone? Why is the jack that goes from the telephone headset to the telephone a different size than the jack that goes from the phone to the wall jack? Is it to idiotproof the process? Also why four wires into the headset? Does the phone itself do anything to the signals before it sends it to the headset? If the proper size jack was put on the headset could you plug that into the wall jack and recieve calls? What do the two wires (red and green or yellow and black) carry? Is one postive and negative like electrical wires? In the case of my second line I bought a double wall phone outlet. I installed the first line (R&G) to the top outline and installed the second (B&Y) line to the bottom outlet. The first line worked the second did not. The second line was live as I have a jack wired right into at the NIU. I then disconnected the wires from the NIU for the first line and reconnected them to the NIU for the second. That got the second line working. That says to me that there must be something physically wrong with the Yellow or Black wires. That seems strange to me as all four wires are in the same cable and if there was a physical break in the cable it would affect all the wires, not just one or two. Any thoughts of this? Thanks for any help. Dennis P.S. Does anybody know the number for ringback for 609-871-XXXX?