Summary

Siemens spark transmitter, consisting of spark gap, inductance coil and key, mounted on wooden base. Made by Siemens Brothers, about 1910.

Physical Description

Two devices, one larger and one smaller, are each mounted on separate polished wooden bases, which are mounted on a single polished wooden base. A third device is mounted directly onto the main base. The larger device (induction coil) contains a large black coil with a vertical brass pillar at each end. One pillar (to the centre of the whole instrument )has a perpendicular brass rod in it with a pointed end facing towards the other pillar, whic does not have a pointed horizontal rod. Two terminals at the end of the coil lead into the main base, while on the other end of the coil, two leads connect to the medium sized device. The medium size device consists of an interupter and a reversing switch. The interupter consists of a pair of coils and a spring mounted armature with one pairs of contacts and an adjusting screw for a rest position of the armature. A plastic bag, attached to the object, contains a screw.

More Information

  • Collecting Areas

    Information & Communication

  • Acquisition Information

    Donation from Unknown Source - Likely Donation, 18 Feb 1978

  • Manufacturer

    Siemens Bros Dynamo Works Ltd, circa 1910

  • Inscriptions

    Metal plate on base supporting coil: Siemens Brothers / London Next to metal plate: 414 Stamped into wooden base at end of central of coil: a e / 224U / 0,18E Terminals labelled C and C are connected to corresponding terminals labelled C and C on the coil. Termainals labelled A and E are connected to the terminals labelled A and E on the coils. Two terminals labelled K and Z are part of the reversing switch. The terminal K is connected to the smallest device - a morse key.

  • Brand Names

    Siemens (Radio Transmitters)

  • Classification

    Communications, Radio, Transmitters

  • Category

    History & Technology

  • Discipline

    Technology

  • Type of item

    Object

  • Overall Dimensions

    810 mm (Width), 220 mm (Depth), 310 mm (Height)

  • Keywords

    Radio Transmitting Equipment