In article ,
Jud McCranie wrote:

OK, but I don't understand what you mean by a three-way connection.
The jack I got working was inside the loop. The blue/white pair of
conductors to the red/green of the jack got it working. For the time
being, I didn't try to get the next jack downline working, since we
don't use it. So how should the 3-way connection be?

If you don't want the stuff "downstream" to work, or there is trouble on the
pair beyond that location, your connection at that location is known as a
"dead end", not a three-way. If you don't "connect through" the conductors of
the loop, you are "dedicating" the pair at that point. This is basic cable
splicing and applies to much common electrical wiring as well as telephony.

If you DO connect all like (matching) conductors, you are making a "tap" or
"three-way" (in-jack-out) connection. This is often done by placing BOTH
like-colored conductors behind the appropriate terminal screw of the device
(jack). Twisting them before placing behind the washer is poor technique.
Placing individual "hooks" of tinned conductor, each behind its own washer,
then slightly expanding/loosening/opening the hook before seating the screw,
is next-to-best. The best tap technique, from a reliability and ease of
trouble shooting standpoint is to connect a short length (8-12-inches) of wire
to the jack - a "stub". Then, using two jellied 3-conductor, solderless
connectors (Scotchloktm), cut-in/splice-in the stub to the loop - a
three-way connection.

A loop-wired home is probably the most confusing component to a DIYer doing
some of their first phone wiring work.

It is a VERY primitive scheme: If the house just disappeared, you would have
one, LONG length of cable. What appears to be two cables in an outlet box (or
plaster ring) is really just a LOOP of that ONE cable, the bulk of which is
permanently behind the walls and ceilings of the premise. Jacks are merely
TAPPED onto a SINGLE pair in that single cable at several points along the
cable. Lengths of cable can be tapped, or three-wayed, onto the main cable at
any point to serve one or more outlets.

After THIS class big grin, you'll want to attend my next one where we'll
cover the installation of a DPST switch that silences every station on the
teenline until the kids' homework and piano practicing are done. That can be
done from an SNID but having the switch mounted on the kitchen wall is the
most convenient.
--

JR

No project too small
All projects too big