Uploaded June 2022 | Updated September 2026, 1 hour ago
How one of the first high speed analog to digital converters used an amazing vacuum tube to achieve 12 million samples per second, and then was forgotten as technology moved on.
The telephone network of early 1965 was primarily an analog network. There were only about 3000, 1.55 megabits per second, digital T1 trunk lines in inter-office service, each with a capacity of 24 simultaneous telephone calls. Back then, most long distance voice communications was over the American Telephone and Telegraph Company’s analog microwave radio and analog cable networks, but AT&T was beginning experiments with high speed digital networking. The goal was to develop equipment for a digital, toll-grade, long haul system capable of transmitting television, and frequency multiplexed, 600 channel telephone master groups. In order to do this Bell telephone labs embarked on the development of this experimental 224 megabit per second analog to digital converter based on an idea from the 1940s.
Help keep communications history alive by becoming a member of the Antique Wireless Association at: antiquewireless.org/homepage/membership
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How one of the first high speed analog to digital converters used an amazing vacuum tube to achieve 12 million samples per second, and then was forgotten as technology moved on.
The telephone network of early 1965 was primarily an analog network. There were only about 3000, 1.55 megabits per second, digital T1 trunk lines in inter-office service, each with a capacity of 24 simultaneous telephone calls. Back then, most long distance voice communications was over the American Telephone and Telegraph Company’s analog microwave radio and analog cable networks, but AT&T was beginning experiments with high speed digital networking. The goal was to develop equipment for a digital, toll-grade, long haul system capable of transmitting television, and frequency multiplexed, 600 channel telephone master groups. In order to do this Bell telephone labs embarked on the development of this experimental 224 megabit per second analog to digital converter based on an idea from the 1940s.
Help keep communications history alive by becoming a member of the Antique Wireless Association at: antiquewireless.org/homepage/membership
Subscribe to the Antique Wireless Museum channel and you'll receive news of our latest video uploads.
