really old phone lines

[salty]

You are still wrong. The telco uses yellow/black for a second line in residential installations. It would make no difference who does the inside wiring, as the telco would still be the ones to wire it THAT WAY where it enters the house. If you take apart any modern analog

2-line phone, you will discover that it is MANUFACTURED to expect the second line to be on the yellow/black pair. Gee, I wonder why?

Please also not that when JK wire is diagramed, the wires are labeled:

green =tip 1 red=ring 2 black= tip 2 yellow ring 2

Case CLOSED

[gfretwell]

That is what an RJ14 jack is labeled but when you use the yellow/black as the second line you get crosstalk. 2 line station wire will usually be blue/blue-white, orange/orange-white twisted pair. That really becomes apparent if you have a modem on one of those pairs. The carrier will bleed over.

[salty]

One more time. If a person calls the phone company and asks to change the existing extension phone in the upstairs bedroom of their 1960's raised ranch to a second line, the telco will come and use the existing 2-pair wiring and use the "unused" yellow/black pair for the second line. The assertion that telcos NEVER do this is pure unadulterated BULL-OH-NEE.

New installations are no longer done with JK 2-pair They now use cat

1. The OP has described the wiring in their new OLD house as being

2-pair with one of the second pair clipped off or missing. There is no blue/blue-white or orange/orange-white there. Does not exist. As I corrected stated, they do not need the black and yellow wires at all unless they want a second line. I told them they just need the red/green pair for what they asked about.

[Mark Lloyd]

[snip]

A lot of the materials I've seen (including wiring diagrams for jacks) say yellow/black is for a second line. Also, if you have a third pair, blue/white for a third line.

I don't know about key systems, but aren't the lights (that use yellow/black) obsolete?

[Mark Lloyd]

[snip]

I have had a second line in here, but the telco put in completely different wiring for it. No cables are shared.

BTW, I later found out they charge over $200 for a little wiring, I could easily have done myself. It's still take new wire, since the old wiring has just 3 wires.

[Wayne Boatwright]

On Mon 25 Aug 2008 10:54:00a, Mark Lloyd told us...

Not if you still have those type of phones. Many people still do.

[Larry W]

Maybe that should read "a telco _should_..." I have seen telco technicians do all kinds of things in residential wiring, including using black/yellow pairs, even green/black or red/yellow, or most any other permutation, if it helps them avoid stringing a new wire at telephone co. expense. I've seen them use wire nuts or twisted wires covered with electrical tape to make their connections. Of course, when it is at the consumer's expense, then they insist on doing everything up to standards. Please don't generalize what is probably best practice to what is actually being done the field.

[hallerb]

yes but some may still be in use.......

bell telephone here, installed second line for business using black and yellow wires, sometime in late 70s early 80s.

[gfretwell]

The old JK only had 3 wires. The 4th (black) wire showed up with the Princess phone. As has been pointed out here, the yellow was for party line selective ringing.

[gfretwell]

Since the late 70s, all interior wiring belongs to the consumer. You don't get anything at telco expense anymore. I also haven't seen an interior phone wired by a real telco installer repairman in years either. They are usually contractors who are basically clueless. Back before the US v ATT decision if you had 2 lines, they ran 2 cables or a 25 pair if you were in an office that might get a call director phone. BSP said you did not run 2 lines in one cable without using twisted pair.

[Uncle Monster]

EEK! Wrong voltage! The nominal DC voltage on a phone line (on hook) is 48 volts DC. The (off hook) voltage can be anywhere between 6 and 12 volts DC. It's the (off hook) loop current in milliamperes that important. 15-36 ma is what I typically see. The US standard ring voltage is 90 volts AC at 20 Hz unless you're on a party line and the ringers will be of the type that are filtered to ring at different AC frequencies. The 48 volts can tingle but the 90 volts will definitely bite you. Don't strip a live phone line with your teeth because that's the exact moment that one of those damn telemarketers will decide to call. If you're looking for good info on phone systems and a source of parts, try

I've purchased phones and parts from the company for years. Oh, the green (tip) and red (ring) wires are the only ones you need for a standard single line telephone as was previously mentioned.

I'll bet you don't know what an "octothorp" is. It's a part of every pushbutton phone.

*snicker* [8~{} Uncle Monster

[salty]

The Princess phone was introduced in the late 1950's. So 4 wire JK has been around at least 50 years now. I personally know of several houses that have telco installed wiring from the 1940's that has 4 wire JK. In 4 wire (two pair) systems, the wires are named as ring and tip ONE and ring and tip TWO. If that's what you happen to have and you are on a party line, then, sure, use the yellow wire for selective ringing. That is NOT however it's official designation ever since the advent of

2-pair wiring - OVER FIFTY YEARS AGO.

Meanwhile, I answered the OP's question correctly, and corrected some misinformation promulgated by others.

See ya.

[Mark Lloyd]

[snip]

Loop impedance is high (IIRC 400 ohms is normal). This causes the voltage to drop considerably when a load is applied (same as in a very old battery). The ring voltage is low impedance.

I thought is was an "octothorpe". Another name is "nanogram", although I don't see that much.

As to something else pushbutton-related, how about the "A" "B" "C" and "D" keys?

[Mark Lloyd]

That's what I thought it was for.

Also, I remember one house built in 1969 that had 6 wire cable:

orange orange stripe on white green green stripe on white blue blue stripe on white

The only wires connected were the 2 in use (I don't remember which 2 it was).

[aemeijers]

Wrong. It is quite common. Most recent time I ran across it was in this very house, where the kid's bedrooms were wired with yellow and black to the center conductors. Pre-cellphone era, Mama Bell heavily sold getting a second line for the kids. Was also quite common with roommates sharing a house (like at college) and wanting private lines to talk to their sweeties, and to make sure there was no question about who pays LD charges. (Back in school, I used to do a lot of moonlight phone wiring for young ladies. Nothing illegal, mind you, just putting outlets where they wanted them.)

-- aem sends...

[aemeijers]

Ask a hard one- that is the 4th row of buttons for an old AUTOVON phone. The TT standard was written around a 16-key (4x4) array. Somewhere in my collection, I have an old gray 2500 without the star and pound keys. Back in the 50s and 60s, the dividing line between ATT, WE, Bellcore, and Army Signal Corp, got rather fuzzy in spots. DoD was heavily involved with the post WWII design of the long-lines buildout. They even used to have a special area code assigned for the government emergency comms- now it is just a front door to a virtual network, with a single phone number assigned to it.

-- aem sends...

[Uncle Monster]

octothorp / octothorpe / octathorp / octatherp

Also called a hash mark and various other things. It has an interesting history.

My understanding is that the letters were found on military phones connected to the AUTOVON phone systems that's no longer in use. I think phone company networks use them for network control and monitoring. I have some butt sets that have the letter keys and some actual phones somewhere in my collection. I was talking to someone today about my great uncle who was a lifer in The US Army Signal Corp. He joined when they were still using two tin cans and a string and I'll bet he was familiar with the AUTOVON system.

[8~{} Uncle Monster

[Larry W]

IF the telco installed a demarc box, that is true. However, at least in my area, a lot of homes were missed. If the owner of such a home calls for a line problem today, the telco is required to repair the line even if it is inside the home, at least up to the junction blocks installed by the phone company back in the ancient past. That is where you will find the funky repairs I was describing. The technicians who make these repairs may well be contractors for the telephone co, I don't know. The telco won't install a demarc box on such a home without a lot of persuasion. I guess their bean counters figure it is cheaper to just repair the wiring, than to repair the wiring AND install the box.

[gfretwell]

I don't know where you heard that but they can put that Dmark on the first time you call them and walk away if their butt set works from the Dmark. The next time you will pay a trip charge. In real life I have not seen a house without a Dmark in almost 30 years. Maybe they are just more proactive in Florida

[Mark Lloyd]

I don't have one (in east Texas), although a neighbor does.