Dial Document Links
These documents are in PDF format
Instructions for maintaining and repairing Dials No. 20
, 1956 (extremely comprehensive).
Aitken: extracts from his book
Automatic Telephone Systems
Maintenance and repair of type 24a36 dial
British Post Office: Dial No. 3 - Siemens Brothers Patent in Montreal -
British Post Office:
Educational Pamphlet 5/1
'Telephone Dials' (training text).
British Post Office: Engineering instructions
(Dial No. 20),
(storage of Dial No. 30),
(dials in general).
Dial No 24 (American) -
Operation and maintenance
Commonwealth of Australia:
Dials in use in 1929
Ericsson Telephones Ltd:
for dials (mid-1950s)
Ericsson Telephones Ltd: Trigger Dials N19877, N4381, N4383A, N43941A (Ericsson/Plessey
DSL1a for Dial No.20, late 1950s.
USA: article on
Dials used in North America
by Bruce Crawford.
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Last revised: November 30, 2021