Strowger calling dial, 1900
- Made:
- 1900 in United States
This image is released under a CC BY-NC-SA 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
LicenseThis image is released under a CC BY-NC-SA 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
LicenseThis image is released under a CC BY-NC-SA 4.0 Licence
Buy this image as a print
BuyLicense this image for commercial use at Science and Society Picture Library
LicenseCalling dial from a Strowger telephone
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Calling dial from a Strowger telephone
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Calling dial from a Strowger telephone
Science Museum Group Collection
© The Board of Trustees of the Science Museum
Calling dial from a Strowger telephone, made by the Automatic Electric Company, United States, 1900.
This calling dial was the first design to use the 'three wire' system which had an earth connection in addition to the two telephone lines connecting to the exchange. Dialling impulses were sent alternately along the two exchange wires, and the earth connection provided the return path. The 'three wire' system was standard until 1907.
Details
- Category:
- Telecommunications
- Object Number:
- 1926-1057
- Materials:
- metal (unknown)
- Measurements:
-
overall: 145 mm x 205 mm x 100 mm, 1.18kg
- type:
- telephone component
- credit:
- Donated by BT Heritage and Archives
Parts
