In article ,
Mark Lloyd wrote:

I think I understand that system now. It would allow 25 unique
combinations. What do you do for more than that?

The first 25-pairs are spiral-wrapped in a white/blue "ribbon". The next
25-pairs are similarly wrapped in a white/orange ribbon. The third group (of
25-pairs) is wrapped with white/green ribbon. The ribbon bundling the 25-pair
groups follow the same color code sequence as the first 25-pairs. This works
up to 600-pairs. Beyond that, the sequence starts over with the addition of a
red ribbon to every 25-pr group. These are known as "super groups" to
indicate the count starts with pair 601.

You should see what it looks like when a backhoe brings up a 900-pair cable
the hard way. Thank God I'm not a cable splicer. Call before you dig.

a 3-pair cable, each pair has a solid color wire (green, blue,
or orange) and a white one WITH A STRIPE of that color.

BOCs (Bell Operating Companies) used 3-pair for probably 15-20 years. The
white/blue pair was used for line one and connected to the red/green posts on
the jack. The third pair (white/green) was used for dial light voltage and
laid down to the yellow/black posts. White/orange was just spare unless it
was used for a second line.

BTW, I have some new phone wire I got at Lowe's in October. The colors
are white, black, red, green, yellow, blue (that's the order they're
shown on the wiring diagrams on the package).

That describes exactly the garbage cable that Menards sells. I would hold out
for cable rated Cat3. I'm guessing there is no "cat" rating on your cable.

However, unless you're running more than one line on the cable (requiring only
ONE pair), rating or twist doesn't really matter. With tight/good connections
and insulated from each other and ground, one can run a POTS line on bailing
wire and coat hangars. More than a few DIYers do.
--

JR

Mean Evil Bell System
Historical Society