In telephony, ground start is a method of signaling from a terminal of a subscriber local loop to a telephone exchange, where one side of a cable pair is temporarily grounded to request dial tone. Most middle 20th-century American payphones used coin-first ground start lines, with the starting ground connection provided by the coin itself, bridging a set of contacts as it passed through the coin chute.
In telephony, ground start is a method of signaling from a terminal of a subscriber local loop to a telephone exchange, where one side of a cable pair is temporarily grounded to request dial tone. Most middle 20th-century American payphones used coin-first ground start lines, with the starting ground connection provided by the coin itself, bridging a set of contacts as it passed through the coin chute.
Source: Wikipedia "Ground start" · CC BY-SA 4.0
Share this article: X · Bluesky