I bought a new, modular, twin-telephone-jack outlet box
cover, and bridged the two jacks to be in parallel.
I added wire-stubs to furnish twist-together jumpers for the
incoming wire (easier to add the stubs on the bench, than to
deal with the screw-connectors, crouched in a dark corner).
I wanted to check continuity, so I cut a modular cord in
half and bared the wires on one half so I could use an
ammeter to check.
What I found was that black & yellow are reversed, and red &
green are reversed. The colors are that way on the plate
that I bought (short wires with forked terminals in the
ends, under the screw-heads). Is this normal? Does it make
a difference? It seems to me that if it didn't make any
difference, there would be no point to having four wire
colors--two of one color, and two of another color would do
By forked terminals do you mean spade lugs? Ar you sure you didn't
make the reversal when you made the measurements. Looking at things
from the front, they are opposite than when looking at them from the
That said, you can usually reverse R + G, and Bl + Yel. Without
knowing what you are connecting, it is impossible to say for 100%
surety. For example, some pots telephones will not work if their
polarity is reversed. You can answer, and can listen and talk, but
the touchpad to output touchtones will not work. Other phones have
internal bridges that solve that problem.
Or where you are.
In the USA, red/green is what most people use.
The black/yellow is for a second phone line.
Are you sure your cable is wired with the proper colors?
On Sun, 30 Dec 2012 20:50:39 -0500, firstname.lastname@example.org wrote:
You know, I just learned that on sci.electronics.repair.
I've been using the terms for about 50 years, and I thought the ring
was the wire the ring came in on, and the tip was the other one, maybe
because it tipped some circuit when the voltage got high enough.
I only figured it out this past summer when I asked about what turned
out to be callled a TRR plug, a tip, ring, ring plug.
Probably a TRS plug - tip, ring, sleeve.
In the good-old-days when phone connections were made through an
operator switchboard with patch cords an extra wire was added to the
subscriber pair at the central office. The extra wire was to determine
whether the pair was already in use. All the operator jacks had to have
connections for all 3 wires - tip, ring, sleeve. The control wire
connected to the sleeve. The operator touched tip of the patch cord plug
- connected to their headset - to the end of the jack, the sleeve. If in
use there was 48 volts (?) and the operator heard a click. Then lights
were added for each jack. Mechanical switching centers also carried a
3rd wire at the central offices.
On 12/30/2012 05:13 PM, email@example.com wrote:
I got a lighted-dial phone in my first apartment (about 1980), however
it was powered by the phone line and lit only during a call.
Someone had left an old transformer connected to the yellow/black wires.
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