Initially, telephones were designed without the capacity to dial,
because calls were connected by a human intermediary. Manufacturers
only started affixing dials in the mid-1920s, when automatic
switchboards began replacing the more personal touch afforded by
These newer systems allowed direct person-to-person calls to be
made through the use of a circular rotating dial, on which each
number was represented.
The rotary dial actually caused the phone to be hung up and
reconnected in rapid succession, with each digit on the wheel being
represented by a fixed number of disconnects. These pulses would
pass down the telephone line, activating the automatic exchange and
connecting a caller to the other party.
It did not take research firms long to begin work on ways to
supplant the rotary dial. In the 1940s, Bell Labs (based in New
Jersey), created a technology called Dual Tone Multi-Frequency (DTMF)
dialing. Each key on a DTMF telephone would create two enmeshed
tones of different frequencies that could be sent across microwave
Use of this technology became possible in Alberta when a
microwave link was established between Edmonton and Calgary in 1957.
As the subscriber list in Alberta grew, so too did the need for
individual phone numbers. Two-letter, five-digit dialing was
introduced in 1959, followed several years later by seven-digit
dialing in 1963.
This growth highlighted certain problems inherent in pulse
technology: Rotary dialing could be time consuming and inaccurate.
More than that, however, pulse signals could only carry so far as
the local exchange. Direct long-distance dialing was impossible.
In order for new technologies such as speed calling to be
feasible in an ever-growing system, phone companies had to explore
the expansion of Touch Button service.
In 1967, Edmonton became the first community in western Canada to
introduce this technology.
While rotary dialing still exists alongside Touch Button technology
both in Alberta and around the world, modern pulse dialing phones
are equipped with a keypad rather than a rotating wheel.
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Heritage Community Foundation and
Telephone Historical Centre All Rights Reserved