• Year
  • 1931–1969
  • Category
  • Morse-Equipment & TTY, RTTY, TDD etc.
  • Radiomuseum.org ID
  • 304093

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Power type and voltage
  • Direct Current supply (DC) / 24; 100-110; 160-250 Volt
  • Loudspeaker
  • - - No sound reproduction output.
  • Material
  • Various materials
  • from Radiomuseum.org
  • Model: Teleprinter 7B - Creed & Company Ltd; East
  • Dimensions (WHD)
  • 490 x 200 x 600 mm / 19.3 x 7.9 x 23.6 inch
  • Notes
  • Creed & Company entered the teleprinter field with its Model 1P in 1924, and introduced the successful Model 3X tape printer in 1927. This machine was manufactured until 1942 and remained in Post Office telegram service until 1949. The Model 7 page printing teleprinter was introduced in 1931 for the new Telex service and the 7B version proved immensely popular, with over 100,000 machines manufactured before production was terminated. Some services were still using them in the 1980s, and prior to the availability of personal computers they were popular for amateur RTTY use.

    With Model 7 machines up to version D, each received character is printed only after the following character is received, but from version E an overlap cam unit allowed the printing to be carried out whether or not another character was being received. Suffix /RP indicates a machine with a tape reperforating attachment, while /RO or Model 8 indicates a receive-only machine without a keyboard. An improved version of the 7E introduced in 1954 was designated Model 54. It was the last of the Model 7 family, as the following Model 75 had a completely different design.

    Although some 7B teleprinters had synchronous AC motors, most had DC motors that can be configured for different voltages, and governors that can be adjusted for 50 or 45.45 Baud operation. The teleprinter illustrated has been fitted with governors for both speeds, selectable by reversing the supply polarity. For speed checking with a 125 Hz shutter-tine tuning fork, the governor case has been marked with 5 white and black segments for 50 Bauds (3000 rpm) and 11 white and black segments for 45.45 Bauds (2727 rpm).

    The machines are usually equipped with a detachable friction-feed page printer that uses 3.5" (8.89 cm) diameter rolls of 8.5" (26.6 cm) wide paper, although they can also be fitted with a sprocket feed platen, or with a 0.375" (9.53 mm) wide tape printer, as with the Model 3X. Unlike the Model 3X, all the machines use ribbon inking.

    The keyboard contacts are a single pole changeover switch, and the selector magnet is normally driven by a bipolar current of about 25 mA, often through series resistors from a +/- 80v supply. An answer-back unit that responds to a WRU query is provided. It is programmable by a series of coded metal tabs, and can also be triggered locally, so that in amateur RTTY service it can be set up to send a CQ call.

  • Net weight (2.2 lb = 1 kg)
  • 25.3 kg / 55 lb 11.6 oz (55.727 lb)
  • Author
  • Model page created by Bruce Taylor. See "Data change" for further contributors.

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The model Teleprinter is part of the collections of the following members.


The model Teleprinter can be seen in the following museums.