In article ,
"TWayne" wrote:
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.
Hmm, please cite your source?
Aw, he can cite ME. I did it for 30 years.
I'd like a look at them for myself. I'm wondering if you aren't
mixing up different RJ families of connectors or
something or whether something has changed.
RJ11
RJ14
RJ21X
RJ31
RJ45
Yadda
Yadda
At least from CFR data on the 'net, nothing has changed so it
would have had to have happened within the last say two to
three years at the most.
Don't believe anything you read and only half of what you see.
(Will Rogers. http://www.willrogers.org/)
I read it on the net so it MUST be true. sigh
Situation:
40-year-old home wired with four conductor "JK" wire. (red/green &
yellow/black)
Customer wants a second POTS line in his home office.
The telco installer connects the new line to the yellow/black pair of
the quad wire at the demarc/SNI/D.
At the "far end", if the yellow/black pair is not already connected to
the formerly-one-line block, the installer has two choices, either one
will be dictated by the customer's need.
If the customer has a two-line telephone and wishes both lines to be
delivered from the wall outlet (jack) to the phone on a SINGLE base
cord, it must be a two-line cord - four conductors.
Wired thusly, the jack is configured as an RJ14. It's the SAME jack
(four pins) but the outer, two pins have been activated with Line 2.
If the customer wishes the new line to be a stand-alone line, the
installer will ADD a jack/RJ11. Red/green will feed one and
yellow/black the other.
I did it so often I could do it in my sleep. Some unfriendly coworkers
would argue that I occasionally did. sigh
Blue/White for what it's worth is part a large jack/connector
combination and nothing you would ever find in the home or even stores
that sell phone equipment unless they also sold key sets, PBXs and what
not.
Where do you GET this info? Man...
White/blue is the color of Pair 1 - yes - the FIRST pair, in any cable.
Mere single-family homes since about the late sixties were wired with
such cable. Such cable is readily available at Home Depot and Lowes.
The white/blue pair is connected to the green/red lugs on a common block
(jack/outlet). White/orange (line/pair 2) is connected to the
black/yellow lugs on the same jack.
I've never even seen pure blue here in the states; only in the UK.
Aw, we have pure blue here, too. ...in the sky.
I don't know about key systems, but aren't the lights
(that use yellow/black) obsolete?
Mostly, yes.
The fourth conductor, to make a second PAIR, was added by the Bell
System many, MANY years ago to facilitate either dial light current, a
spare pair in the event of failure of the first, or the need for a
second line.
Dial light transformers were introduced in the late 50s or early 60s to
illuminate the lamps inside the (then) new Princessr telephone. The
Trimliner phone followed shortly with an illuminated dial.
When dial light became "line powered", it was no longer necessary for a
dedicated transformer somewhere in the house - the ORIGINAL wall wart.
There are probably hundreds of thousands of such transformers still in
service today - virtually unused.
--
JR