Loading coil, 1910-1930

Loading coil, 1910-1930 Loading coil, 1910-1930

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Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Loading coil, unknown maker, probably British, 1910-1930.

The performance of a long-distance telegraph or telephone cable can be improved by 'loading' it with additional inductance to balance the capacitance effect caused by the cable being surrounded by air (a non-conductor). The principle was conceived by Oliver Heaviside in Britain and brought into practical use by Michael Pupin in the USA. The advent of electronic repeaters eventually made loading coils unnecessary.

Details

Category:
Telecommunications
Object Number:
2014-60
Materials:
copper (metal) and fibre (unidentified)
Measurements:
overall: 50 mm x 85 mm diameter, 0.422 kg
type:
coil
credit:
Donated by BT Heritage and Archives