CMS:803C Ringing and Tone Plant: Difference between revisions

(One intermediate revision by one other user not shown)

Line 1:

[[File:A photo of the 803C ringing plant at the museum.jpg|thumb]]

[[File:Ringing Machines in West.jpg|thumb]]

The 803C Ringing and Tone ~~plant~~ is an exhibit that demonstrates how ringing and tones were created in large metropolitan areas in the Bell System. It consists of a P-type motor generator set (known as a ''ringing machine'') which was salvaged from the [[West central office|West office]] in Seattle, and a control board that served the Pearl St. office in Hartford CT. This tone plant was notable for creating the sweet sounding "city ring" tones that were emblematic of AT&Ts service in large cities for much of the 20th century.

The '''803C Ringing and Tone Plant''' is an exhibit on the third floor of the Connections Museum that demonstrates how ringing and tones were created in large metropolitan areas in the [[wikipedia:Bell_System|Bell System]]. It consists of a P-type motor generator set (known as a ''[[ringing machine]]'') which was salvaged from the [[West central office|West office]] in Seattle, and a control board that served the Pearl St. office in Hartford CT. This tone plant was notable for creating the sweet sounding "city ring" tones that were emblematic of AT&Ts service in large cities for much of the 20th century.

== Background ==

Line 16:

== Museum Life ==

In 2023, space was allocated in the museum for the new ringing plant. Several smaller exhibits were moved, and the area was streamlined to provide a more interactive and better experience for visitors. Although there were two ringing machines salvaged, (one powered by AC, the other by DC), it was decided to use the DC machine, because it was in much better condition, and it could easily be run on the museum's existing 48V battery plant.

The equipment was assembled by volunteers Sarah Autumn and Jay DeJaen in August - December 2023. Volunteer Eric Rhinelander built a custom steel table for the machine, and the original slate tabletop was bolted to the steel framework.

The ringing machine and control board had no official schematics detailing how to wire them together, so Sarah and Jay made custom cable forms using available schematics as a starting point. Several modifications were also made to the control board that integrated older equipment from the West office. These modifications include the double-throw knife switch, and the old style voltage regulators mounted on the board. A speaker was also mounted in the side of the cabinet with a rotary switch that allows visitors to hear the various tones that the machine generates.

The ringing plant provides ringing and tones for the [[CMS:Number One Crossbar Switch|1XB]] and [[CMS:Panel Switch|Panel]] switches, and is integrated into the floor alarm board (FLA 100) in the 1XB. Any alarms are sent there, and are displayed as lighted lamps on the wooden annunciator over the [[CMS:Power Board|power board]].

@@ Line 1: / Line 1: @@
 [[File:A photo of the 803C ringing plant at the museum.jpg|thumb]]
 [[File:Ringing Machines in West.jpg|thumb]]
-The 803C Ringing and Tone plant is an exhibit that demonstrates how ringing and tones were created in large metropolitan areas in the Bell System. It consists of a P-type motor generator set (known as a ''ringing machine'') which was salvaged from the [[West central office|West office]] in Seattle, and a control board that served the Pearl St. office in Hartford CT.  This tone plant was notable for creating the sweet sounding "city ring" tones that were emblematic of AT&Ts service in large cities for much of the 20th century.
+The '''803C Ringing and Tone Plant''' is an exhibit on the third floor of the Connections Museum that demonstrates how ringing and tones were created in large metropolitan areas in the [[wikipedia:Bell_System|Bell System]]. It consists of a P-type motor generator set (known as a ''[[ringing machine]]'') which was salvaged from the [[West central office|West office]] in Seattle, and a control board that served the Pearl St. office in Hartford CT.  This tone plant was notable for creating the sweet sounding "city ring" tones that were emblematic of AT&Ts service in large cities for much of the 20th century.
 == Background ==
@@ Line 16: / Line 16: @@
 == Museum Life ==
+In 2023, space was allocated in the museum for the new ringing plant. Several smaller exhibits were moved, and the area was streamlined to provide a more interactive and better experience for visitors. Although there were two ringing machines salvaged, (one powered by AC, the other by DC), it was decided to use the DC machine, because it was in much better condition, and it could easily be run on the museum's existing 48V battery plant.
+The equipment was assembled by volunteers Sarah Autumn and Jay DeJaen in August - December 2023. Volunteer Eric Rhinelander built a custom steel table for the machine, and the original slate tabletop was bolted to the steel framework.
+The ringing machine and control board had no official schematics detailing how to wire them together, so Sarah and Jay made custom cable forms using available schematics as a starting point. Several modifications were also made to the control board that integrated older equipment from the West office. These modifications include the double-throw knife switch, and the old style voltage regulators mounted on the board. A speaker was also mounted in the side of the cabinet with a rotary switch that allows visitors to hear the various tones that the machine generates.
+The ringing plant provides ringing and tones for the [[CMS:Number One Crossbar Switch|1XB]] and [[CMS:Panel Switch|Panel]] switches, and is integrated into the floor alarm board (FLA 100) in the 1XB. Any alarms are sent there, and are displayed as lighted lamps on the wooden annunciator over the [[CMS:Power Board|power board]].