The General Post Office took over the telegraph services from the then existing
private telegraph companies in 1870, thereafter the telegraph service was
rapidly developed throughout the length and breadth of the country.
Morse key and sounder and later Charles Wheatstone's ABC telegraph were the
instruments of early telegraphy.
In 1897 Frederick George Creed came up with an idea for a revolutionary telegraph
machine. Many designs later, the General Post Office placed an order for
12 machines which consisted of a tape perforator operated by compressed air
and controlled by a keyboard similar to that of a typewriter.
More Creed information found at:
http://home.iprimus.com.au/oseagram/creed2.html
The first teleprinter used in the British public telegram service was the
Creed model 3, a combined start-stop transmitter/receiver. No carriage-return
(C/F) or line-feed (L/F) was needed also a space bar was omitted. The Figs
bar and Ltrs bar each had a space character built in so telegram users had
to accept a space before and after a change of shift. This was eventually
replaced by the teleprinter number 11B (Creed model 47) with the introduction
of teleprinter automatic switching.
This teleprinter was used in conjunction with a dial unit containing switching
relays and operating at +80 and -80v.
Power supply for the motor was 160vdc. In the larger offices, both the relay
and motor supplies were taken from the main office +-80v battery being
float-charged from a rectifier installation so that service was un-interrupted
by any mains failure. Although we had such battery supplies, they did not
have the capacity to supply current for all the teleprinters so could not
handle prolonged power strikes which brought our office to a halt apart from
phonograms - we could only run a dozen fairy lights on it!
Larry
Rice OTO1 Birmingham ITAO
1961-1982 11/10/1999 +++++++
