Telegraph Sounder
Telegraph Sounder
- Description (Brief)
- Telegraph sounders convert electrical pulses into audible sounds and are used to receive Morse code messages. The message travels as a series of electrical pulses through a wire. Short pulses make a dot, slightly longer pulses make a dash. The sequence of dots and dashes represent letters and numbers. The pulses energize the sounder’s electromagnets which move a lever-arm. The arm makes a loud “click” when it strikes a crossbar and the operator translates the pattern of sounds into the original language.
- This small, portable telegraph unit was known (probably generically) as a "secret sounder" and could be attached quickly to a telegraph line for military use or for tests by maintenance crews. Containing both a key and a sounder in a closed box, the unit is associated with US Patent #760029, issued to John F. Skirrow on 17 May 1904. The patent does not specifically mention a secret sounder but explains a method of adjusting the position of the electromagnets in a sounder (or "other forms of electric signaling instruments") without affecting the angle between the armature and magnet cores. Skirrow also claimed that his innovation resulted in a simpler way of adjusting sounders.
- Location
- Currently not on view
- Object Name
- telegraph receiver
- telegraph sounder
- date made
- ca 1905
- maker
- Skirrow, John F.
- Physical Description
- brass (overall material)
- wood (overall material)
- steel (overall material)
- Measurements
- closed: 1 3/4 in x 6 1/2 in x 4 1/2 in; 4.445 cm x 16.51 cm x 11.43 cm
- open: 2 1/4 in x 6 1/2 in x 4 1/2 in; 5.715 cm x 16.51 cm x 11.43 cm
- ID Number
- EM.331454
- patent number
- 760029
- collector/donor number
- 100-817
- accession number
- 294351
- catalog number
- 331454
- Credit Line
- from Western Union Corporation
- See more items in
- Work and Industry: Electricity
- Communications
- Telegraph Sounders
- Data Source
- National Museum of American History
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Comments
Hal Wallace
Wed, 2020-08-19 09:56
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THOMAS HORNE
Thu, 2020-08-13 09:44