page_title: Push-button telephone
section_title: Pulse dialing
hierarchical_section_title: Push-button telephone / Pulse dialing
caption_attribution_description: Iskra ETA85-S telephone set with pulse-dial key pad. Made in Yugoslavia, 1988
context_page_description: The push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to having a rotary dial as in earlier telephone instruments.
  Western Electric experimented as early as 1941 with methods of using mechanically activated reeds to produce two tones for each of the ten digits and by the late 1940s such technology was field-tested in a No. 5 Crossbar switching system in Pennsylvania. But the technology proved unreliable and it was not until long after the invention of the transistor when push-button technology matured. On 18 November 1963, after approximately three years of customer testing, the Bell System in the United States officially introduced dual-tone multi-frequency technology under its registered trademark Touch-Tone. Over the next few decades touch-tone service replaced traditional pulse dialing technology and it eventually became a world-wide standard for telecommunication signaling.
  Although DTMF was the driving technology implemented in push-button telephones, some telephone manufacturers used push-button keypads to generate pulse dial signaling.
context_section_description: Historically, not all push-button telephones used DTMF dialing technology. Some manufacturers implemented pulse dialing with push-button keypads and even Western Electric produced several telephone models with a push-button keypad that could also emit traditional dial pulses. Sometimes the mode was user-selectable with a switch on the telephone. Pulse-mode push-button keypads typically stored the dialed number sequence in a digit collector register to permit rapid dialing for the user. Some push button pulse dial phones allow for double-speed pulse dialing. These allow even faster pulse dialing in exchanges that recognize double-speed pulse dialing.
  As telephone companies continued to levy surcharges for touch-tone service long after any technical justification ceased to exist, a push-button telephone with pulse dialing capability represented a means for a user to obtain the convenience of push-button dialing without incurring the touch-tone surcharge.
caption: Iskra ETA85 pushbutton telephone with pulse-dialing keypad (Yugoslavia, 1988).
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