187 lines
9.4 KiB
Plaintext
187 lines
9.4 KiB
Plaintext
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* *
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* The Telephone Works *
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* Egghead Dude *
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* CHiNA CHiNA *
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***************************************************************************
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Welcome to CHiNA Educational InfoFile Series II, # 3. Once again,
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be looking for new files weekly for the next few weeks until school starts
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again. And contrary to Megaton Man's belief, we are still very much alive
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and in production. If he tells you otherwise, kindly call him a peasant
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and tell him to fuck himself...if you want. Enjoy!
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Here are the standards in Telephone Color Coding:
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Telephone circuits are paired as 'tip' and 'ring' wires. On POTS
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(plain old telephone service) tip is 0 volts and ring is -48 volts (tip is
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not 'ground' though as it is a blanced line). The pairs must be
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distinguishable from one another easily so they are colour coded. The
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colour of the wire indicates whether it is tip or ring. In a quad wire
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green and black are tip while red and yellow are ring.
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pair# tip colour ring colour
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_____ __________ ___________
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1 white blue
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2 white orange
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3 white green
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4 white brown
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5 white slate (silver)
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6 red blue
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7 red orange
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8 red green
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9 red brown
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10 red slate
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11 black blue
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12 black orange
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13 black green
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14 black brown
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15 black slate
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16 yellow blue
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17 yellow orange
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18 yellow green
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19 yellow brown
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20 yellow slate
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21 violet (purple) blue
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22 violet orange
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23 violet green
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24 violet brown
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25 violet slate
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An individual wire is identified by it's colour and the colour of
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it's stripe. The main colour determines whether it is tip or ring while
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the stripe identifies it's pair (i.e. a black wire with a blue stripe is
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tip of pair 11). In many cables the stripe is missing in which case the
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pairs are distinguished by the way they are twisted, by pulling back the
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sheath pairs are more obvious.
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As you can see there are only 5 tip colors and 5 ring colours (5
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x 5 = 25). a 100 pair cable is made up of four of these 25 pair bundles.
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The first bundle is wrapped by a white/blue binder string, the second by a
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white/orange binder, the third by a white/green and the fourth by a
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white/brown. This scheme can be extended infinitum.
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Some folks think that the order is:
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Pair Tip Ring
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1 RED GRN
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2 YEL BLK
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3 BLU WHT,
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and that the 1st pair was backwards in a modular connector compared to the
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rest.
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Wrong. The polarity is off. Modular connectors reverse the polarity
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so they make the issue pretty confusing. A modular line cord (that is a
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properly made _telephone_ line cord) has a flat topology such that when
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laid on a table the top of both connectors is up. This means that a
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reversal (polarity wise) takes place. Tip becomes ring on all pairs (the
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wire is a ribbon in theory). the top of both connectors is up. A 'set'
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jack (the one inside the telephone) is wired backwards to compensate.
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In addition, the system employed throughout the (used-to-be) Bell
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System was actually very simple. There wer five colors assigned to "tip"
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and five colors assigned to "ring". This gives a total combination of
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twenty-five pairs (very convenient!).
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The colors assigned to the "tip" are;
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white wt
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red rd
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black bk
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yellow yl
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violet vi
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The colors assigned to the "ring" are;
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blue bl
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orange or
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green gr
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brown br
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slate sl (sometimes mistakenly called gray)
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Standard phone convention is to identify the "tip" first and then the
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"ring" when referring to a pair. Thus, the first five pairs of a telephone
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cable are the "white" pairs;
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white/blue wt/bl
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white/orange wt/or
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white/green wt/gr
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white/brown wt/bn
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white/slate wt/sl
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The next five are the "red" pairs:
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red/blue rd/bl
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red/orange rd/or
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red/green rd/gr
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red/brown rd/bn
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red/slate rd/sl
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And so on, until all twenty five pairs are identified. What happens
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when there are more than twenty-five pairs in a cable? Simple, enclose
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each twenty-five pair group in a color coded binder. And guess what the
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color coding is for the binder. Yep, the same as the wires in the binder.
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The first binder group is the "white/blue" binder the second is the
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"white/orange" binder, and so on. If it is necessary to refer to the
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twenty-sixth pair of a fifty pair cable it is referred to as "two
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white/blue" or 2-wt/bl. The seventy-ninth pair in a one-hundred pair cable
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is called "four white/brown" or 4-wt/bn. This all holds true for the first
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twenty-four binders in a cable. The twenty-fifth binder is a little
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different, and my recollection is a little hazy but I believe the binder
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colors are white-white-blue. Yes that's two whites and a blue. It might be
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two blues and a white. It's been a long time since I was in a cable over
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six hundred pairs. One thing I know for sure is that they double up on one
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of the binder colors after the twenty-fourth binder group.
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There is also a convention for the positioning the pairs on
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connecting blocks. The Ring is usually on the Right and the Tip is
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usually on the Top. As you can see there is a pattern here, Ring-Red-
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Right and Tip-Top. I guess this was done to make it easier for us dumb
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installers to remember! |-)
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The only difference in the color coding between telephone cable (the
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stuff used outside and strung along poles or underground in conduit) and
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telephone inside wiring (the gray colored stuff in the walls and up in the
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ceiling) is that the inside wire has each pair traced with the color of
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its mate. That is, the first pair is a white wire with a blue tracer and
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its mate is blue with a white tracer. This is done to avoid "splitting" a
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pair. Splitting is getting the ring of one pair and the tip of another.
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In outside phone cable each pair is twisted with its mate and the chances
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of splitting a pair are not as great (although it's been known to happen
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;-)).
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With wiring done inside a house, a little history is in order. Back
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when we had party-lines,(I know, we still do, but very few still in
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service and none available for new service) three wires were necessary
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because a ground was required to make the bell ring. So, the original
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phone wiring had three conductors, red, green and yellow. Red and green
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were ring and tip respectively and yellow was the ground. Then people
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started getting away from party lines and into princess and trimline
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phones with lights in the dial. The yellow was no longer the ground and a
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black wire was added and the yellow and black were used to supply power
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for the lamps from a small transformer. Time marches on, and now people
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are getting second lines installed in their homes. Since the new phones
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get the power for their lamps from the phone line directly, the yellow
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and black are now "spare". The yellow is usually the ring and black is
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the tip. Of course, houses that have been pre-wired with six-pair inside
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wire would normally have line 1 on the white/blue pair and line 2 on the
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white/orange pair. In many pre-wire installations I have found that the
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sixth pair (red/blue) was used for transformer power, although I don't
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believe that was ever an official practice.
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Written by: Egghead Dude Edited by: The Conflict
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Golf City BBS
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CHiNA Node #5
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Hope you enjoyed this one, and once again, look for more! Please
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distribute this file freely, and if you really must speak to CHiNA,
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contact us on one of our member boards (a node list should be available
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wherever you receieved this file). Thanks for you support!
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A big HELLO to Mr. X, The Maestro, Barimor (hear you're doing wonders
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for the FiRM!), Jolly Green Giant, Feetsack, Lord Blix, Maxwell Smart, The
|
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Viper, etc...if you want to be said HELLO to, too bad, we don't like you!
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Really...we'll be seeing you!
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