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Telegraph Key - Reversing, circa1900 Reg. No: ST 043253
- Reversing telegraph key used for the transmission of signals in the electric telegraph system.
This type of key was used in conjunction with long submarine telegraph cables which distorted electrical signals so that the normal on-off pulses used in land telegraphy to mark the dots and dashes of Morse code would not work. Instead, the direction of flow of signal current was changed so that current flowing in one direction signalled a dot and in the other direction a dash. The reversing key used two separate keys, one for each direction of current flow.
At the receiving end the sequence of current pulses were displayed as a wavy line on a moving paper tape which could be interpreted by the operator .
Similar to keys made by Elliott Bros., London, but no maker's name or details. Probably made in Europe about 1900.
- Two brass spring switches with ebonite knobs mounted on ebonite pillars. Cam adjustments for spring movement. All on ebonite base.
- Acquisition Information:
- Unknown from Unknown
|Dimensions:||88 mm (Height), 109 mm (Width), 137 mm (Length)|
|Tagged with:||electrical apparatus instruments, electrical switches, morse keys, physical apparatus instruments, telegraph equipment, telegraphy|
|Themes this item is part of:||Australia and the global telegraph network 1854-1902, The Australian telegraph network 1854-1877, Telegraphy Collection, Information & Communication Collection, Science & Measurement Collection|
|Date Made:||circa 1900|