Telephone conductors and Internet transmission

Does this have any known effect on opening Internet pages?
This morning I tried to use a fitting to splice an extension line onto our main telephone line, coming off the utility post; unfortunately the extension wire couldn’t be run up into the room (through a hole in the floor) because it was too narrow.
However, I also noticed that the phones fed by that line in the first place, went dead. When I took the fitting off (red, yellow, green and black wires screwed to terminals on the junction block and a third line branching off it) and tied the lines back together, the phone worked again.
This phone line only has the wires that are insulated in red, yellow, and green; no black. When I first got the computer and plugged its modem into the jack connected to that line, it worked fine. When I hooked it later to a line with neither yellow nor black connected, I kept getting (on BlueLight but sometimes also on AOL) the “Cannot Find Server” message.
Does the yellow-insulated line figure in this? :confused:

IANA Telephone repairman. But from my experience, even though telephone wires and jacks have 4 wires, only 2 are used. Back in the day, I guess they needed one set for the microphone and one for the speaker but like I said, now a days they can get away with using 2 wires. That alowed my dad to have 2 phone lines without rewiring the house with a second wire.

A common error that people make when installing telephone wiring is to use 4-conductor (non-twisted) cable. This can cause problems with modems and makes your telephone more susceptible to interference and noise. You should use 4-conductor twisted-pair telephone cable. Normally, the first pair (red and green) is used for the first line, with the second pair (yellow and black) used as a spare or for a second line.

The early telephone is a marvel of creative engineering. For just about any electrical signal you need two wires. They managed to put the ring signal, a signal to tell if the phone was on or off the hook, voice going out, and voice coming it, all on two wires. And, they did this all with just some fancy coils of wire, a switch, and a very primative speaker and microphone. The ring signal is 90V 20 Hz AC, which will make an electromechanical bell ring with no additional circuitry required. When you pick up the phone, this closes a switch which lets DC current flow through the two wires, so the switching station can tell that you picked up the phone. The voice signals work by modulating the current that is flowing through the wires. A very craftilly constructed coil makes it so that the voice going out is quieter than the voice coming in.

Pretty damn crafty if you ask me.

There were early systems that did use seperate wires for the speaker and receiver, which was an attempt to get around the problem of hearing your own voice too loud in your own earpiece (before someone invented the fancy coil that allows you to do this with only 2 wires). This was back in the day when the phone had the earpiece that you picked up and put on your ear, and you spoke into the base (one of these:

The yellow & black wires were actually used at one time to provide electrical power to some early phones (princess or trimline models) that had built-in lights in their dials.

Way down in a storage room in the basement of my house, where the phone lines come in, there was a small transformer plugged in with wires running to connect to the yellow & black phone wires. But it’s been disconnected for at least 20 years.

If you have DSL, it’s more complicated, but if you have dial-up, you can quick-test the line by connecting a regular phone. See if you can get dial tone, dial out, and talk.

Modems are so amazingly designed to work over a voice line that if your ear doesn’t hear a problem, most often it’s good enough for a modem. So this test is a little crude, but quick.

In fact, the direct line that now plugs into my modem also powers three extension phones, because of an outgoing line on the back of my computer console. There are two extensions in my own room (with a switch to select one or the other, to use; one is near the computer and the other is on my night stand) and a third in my Mom’s room. (The remaining extensions are the ones connected to the line I wanted to splice; it runs below the fcloor. The extensions are in the dining room and I wanted to connect one in the living room.)

I tried twisted-pair wire, and it didn’t work. It was a maddening task to thread the line below the floor; and I didn’t have it all that lonig before it failed. So I replaced it with conventional wire.
No, I don’t have any problems with the phones–just the Internet connection.

If you can plug a phone into the new jack and get dial tone and make calls, a modem should work on that jack.

It sounds like you’ve got several phones connected to the modem on an outgoing line - if you have the “line” and “phone” jacks mixed up, your modem won’t be able to connect at all, but the phones will probably work OK.

The yellow and black wires shouldn’t be involved, but there’s no guarantee that someone in the past didn’t do something goofy like wiring up the line on red and black, rather than red and green.

Normally, you’ll have all the reds connected to reds, greens connected to greens, and so on.

Just be glad you’re not working with DSL - it doesn’ take much to impair that signal and turn a 6 megabit line into a 1 megabit line.

I connected this computer modem to our phone line in Spring 2002. About three years before that, our phones failed, and it turned out that so much water had seeped into an old Pacific Bell underground junction box that it conked out. Pac Bell came around and replaced the junction box (and the terminal at our mobile-home site) with new equipment.
Here, however, is a frustration and a mystery: the terminals on the top work just fine; the modular receptacle and the wire terminals for the other two positions (middle and bottom) on our utility terminal don’t work at all.

Sounds like you need to call SBC and have them check out the terminal box. (Also known as an MPOE or demarc)

You are talking about the box with one or two modular jacks that have short wires plugged into them, and a set of screw terminals immediately next to them? Looks more or less like this or this? If so, that’s SBC’s responsibility to maintain and repair as needed.

The second one looks more like the one we have. The top set of connections works, the other two don’t. I guess I will have to call SBC about that. Maybe they only saw fit to power the connection at the top when they replaced the old hardware…

Are you paying for two dial-tone lines from your phone company? If I read the photos right, the top one is for your first phone number and the lower one is for the second.

The color code in-house would be red & green for the first Telco line, black and yellow for the second (unless you use two separate pairs rather than one quad); from the Telco side it would be white-blue blue-white for the first, white-orange orange-white for the second.

So far as I know, all of the hardware is for the same phone number. Since this is a single residence I doubt they would have installed equipment to accommodate more than one number unless we specifically requested it, or, at the least, the installers told us it was for two or more numbers.

Right, you would have had to request (and be billed for) two numbers. It looks as if they installed the hardware for two numbers. This is probably standard to allow for your adding a second number some day, saving them costs if you do, and probably two extra wires arrive at that equipment from the phone company side. They can be used for the additional phone number if wanted–just hook it up at the Central Office end.

But that connection would be dead until then, it would have no dial tone or DC charge until activated.

Best way to add extensions yourself in-house is to get some form of contact strip or single-to-multi RJ11 jack, and it sounds as if you have something like this.

Wiring diagram:

====="=====phone 1
     "====phone 2
     "===phone 3

Hook the single pair to the top jack at their equipment, and provide yourself several in-house lines, run under the floor or stapled along a molding or wherever convenient but not vulnerable.

Have you connected a phone in place of your modem and tried it? If the signal is very faint, that plus the modem issue would make me suspect one of the two individual wires is open–not connected properly. Most likely place for that is where it is connected, at the modem end or a terminal post; rarely the conductor might break in the middle when horsed around an angle.


once upon a time someone may have used the yellow or black as a conductor in place of the red or the green (red & green should be conn’d all the way from the phone company to your modem*). So that would be called a split pair, and act like a single open wire.

*and all the way, through the terminal “tap” point, to each phone. Red and green at each phone. Of course, the electrons don’t know what color the wire is, but that’s the easiest way for the humans to keep track.

Or, if someone is on the phone when your modem tries to do its thing, the modem loses.