The Hughes system was a rival to the Baudot printing telegraph system. The piano key layout required minimal training for the operators. Messages were printed on paper tape by the type-wheel arrangement visible at the back. Power was supplied by a weight and pulleys underneath.
The single-needle system used alternating polarity of current to pull the needle to one side or the other. It contacted a metal plate or peg, giving a distinctive sound for each side. The code used was similar to Morse code, but dots and dashes were replaced with the two different pitch notes emitted by the plates.
In order to maximise traffic on the expensive long-distance telegraph circuits, automatic morse sending was common. The messages were prepared off-line on paper tape using a machine like this. The tape was then sent at high speed with an automatic sender.
A human operator could not receive the high-speed Morse transmissions sent by the above means. This device made ink marks on the strip of paper visible passing between the rollers. The tape could then be decoded at leisure.
Invented in 1902 by New Zealander, Donald Murray, this printing telegraph system was based on the Baudot multiplex system but the code used was designed to minimise mechanical wear, rather than be easy to remember.
From the Creed factory in Croydon, the Post Office Perforator No1 was used to prepare Telex tape off line. A character counter caused the lamp on the left to light when a line of text was nearly full, allowing the operator to enter a carriage return and line feed at the appropriate point.
Introduced in the 1930s, this page-printing teleprinter was the mainstay of the Post office's Telex service for over 30 years. The type head is fixed and the platen moves from right to left. The unit on the right form the interface between the printer and the Telex network allowing the user to connect calls automatically using the dial.
The traditional stock ticker as seen in many films. The messages are printed on paper tape which exits from the printer at the bottom right.
The Cheetah brought to telex operation all the advantages of a word processor - screen editing, near silent operation when sending, etc. However, the electronic telex machine had a short lifespan compared with its mechanical predecessor, which reigned supreme for over forty years. This was mainly due to the rapid rise of the personal computer, which, with minimal additional hardware, could outperform this dedicated hardware and do a lot else besides.
Exhibits: British Telecom Collection
Photos: copyright Sam Hallas 1992-1997