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Bud--

wrote:
On Tue, 23 Sep 2008 04:01:38 +0000 (UTC), (David
Combs) wrote:

In article ,
Jim Redelfs wrote:
In article _x3tk.43458$hx.13021@pd7urf3no,
Tony Hwang wrote:

Just one: The Western Electric 500 (for example) ringer could be wired
for Tip service or Ring service.

Did "tip" and "ring" have something to do with the (tiny) "central office",
where the two women sat in front of this big board in which you actually
connected the phone calls, by pulling out a wire-and-plug (from the
caller's line?) and then stretched it across the board and plugged
it into the callee's socket, thus "connecting" the call, and then
maybe via crank or perhaps button, generated the "ringing" of the
bell on the callee's phone?

David

Close, but no cigar. Tip and Ring are the parts of one of those 1/4
inch phone plugs they used. The plug is divided into two parts with an
insulator separating them. There is the tip at the end, and the shaft
portion is the "ring"

Actually the plug is divided into 3 parts. The shaft is the "sleeve".
The "ring" is a ring between the tip and the shaft.

"Sleeve" is a 3rd wire used in the central office to determine if the
line is busy. In the switchboard days, the operator could touch the tip
of a patch cord to the shaft part of a jack and if they heard a click in
their earphone the line was busy. On some boards it could light an
adjacent bulb. "Sleeve" continued into the mechanical switching
equipment, and there must be a digital equivalent in modern electronic
switches.

--
bud--