# \#communications
**URL:** https://scanalyst.fourmilab.ch/tag/communications/976.md
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## [The Life & Times of Claude Shannon](https://scanalyst.fourmilab.ch/t/the-life-times-of-claude-shannon/4185)
**Author:** [@Gavin](https://scanalyst.fourmilab.ch/u/Gavin)\
**Replies:** 22\
**Last updated:** [29 January 2024 15:57 UTC](https://scanalyst.fourmilab.ch/t/the-life-times-of-claude-shannon/4185 "2024-01-29T15:57:06Z")
“A Mind at Play: How Claude Shannon Invented the Information Age”, by Jimmy Soni & Rob Goodman, ISBN 978-1-4767-6668-3, 366 pages (2017). Claude Shannon (1916 - 2001) once said: “A very small percentage of the populat…
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## [Apollo Spacecraft S Band Communication System, Part 29—Astronaut Voice Downlink](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-29-astronaut-voice-downlink/4131)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [23 December 2023 14:39 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-29-astronaut-voice-downlink/4131 "2023-12-23T14:39:11Z")
Voice transmissions from astronauts on board Apollo spacecraft were encoded as a frequency modulated (FM) signal which was, then, multiplexed onto the S band microwave downlink from the spacecraft to ground…
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## [Apollo Spacecraft S Band Communication System, Part 27—Adding Quindar Tones to Voice Communication](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-27-adding-quindar-tones-to-voice-communication/3104)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [29 April 2023 12:35 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-27-adding-quindar-tones-to-voice-communication/3104 "2023-04-29T12:35:54Z")
If you’ve heard recordings of the voice communications during the Apollo program, you may have noticed the beeps at the start and end of transmissions from Earth (but not on those from space). …
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## [Apollo Spacecraft S Band Communication System, Part 26—Complete System Integration, Trade Show Demo](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-26-complete-system-integration-trade-show-demo/3059)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [18 April 2023 12:08 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-26-complete-system-integration-trade-show-demo/3059 "2023-04-18T12:08:46Z")
Over 25 episodes, the restoration team has brought up and tested individual components of the Apollo spacecraft communication system and ground station equipment. Now it’s time to put it all together and d…
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## [Apollo Spacecraft S Band Communication System, Part 25—Central Timing Equipment](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-25-central-timing-equipment/2874)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [12 March 2023 15:33 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-25-central-timing-equipment/2874 "2023-03-12T15:33:24Z")
As the project to reassemble an Apollo Command Module’s communication and electronics system from original equipment continues, the next peak to be scaled is the Central Timing Equipment: the box which gene…
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## [From 1956—Western Union Text Communications Network](https://scanalyst.fourmilab.ch/t/from-1956-western-union-text-communications-network/2551)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [3 January 2023 14:04 UTC](https://scanalyst.fourmilab.ch/t/from-1956-western-union-text-communications-network/2551 "2023-01-03T14:04:05Z")
In the early 1970s, I visited a Western Union switching hub near St Louis, Missouri in a tour arranged for attendees at a Univac user conference. By then, all traffic was switched by computers, with outbou…
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## [Apollo Spacecraft S Band Communication System, Part 24—Interface Simulator](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-24-interface-simulator/2431)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [11 December 2022 13:50 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-24-interface-simulator/2431 "2022-12-11T13:50:26Z")
Not only was the Apollo space to ground communication system extraordinary complicated and composed of numerous intricately-related parts, the need to simulate everything on the ground before committing it …
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## [Apollo Spacecraft S Band Communication System, Part 23—Connectors and a Control Panel](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-23-connectors-and-a-control-panel/2280)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [11 November 2022 13:49 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-23-connectors-and-a-control-panel/2280 "2022-11-11T13:49:44Z")
Putting all the pieces together of the Apollo spacecraft communication system requires a control panel with a bewildering array of switches, dials, and knobs, and connectors to hook up all the various boxes…
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## [Apollo Spacecraft S Band Communication System, Part 22—Colour TV from the Moon](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-22-colour-tv-from-the-moon/2096)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [3 October 2022 11:33 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-22-colour-tv-from-the-moon/2096 "2022-10-03T11:33:52Z")
How did NASA send colour television from the surface of the Moon? It wasn’t easy, involving a high gain antenna deployed by the astronauts, a spinning colour wheel in the camera, a tricky modulation scheme…
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## [NASA's Deep Space Network](https://scanalyst.fourmilab.ch/t/nasas-deep-space-network/2022)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 5\
**Last updated:** [19 September 2022 06:31 UTC](https://scanalyst.fourmilab.ch/t/nasas-deep-space-network/2022 "2022-09-19T06:31:24Z")
To see the status and current activity of the Deep Space Network at any time, visit the Deep Space Network Now site. Click on an antenna to see details of the antenna and the spacecraft with which it is cu…
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## [Apollo Spacecraft S Band Communication System, Part 21—Television from the Moon](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-21-television-from-the-moon/1885)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [21 August 2022 14:25 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-21-television-from-the-moon/1885 "2022-08-21T14:25:34Z")
The original slow-scan video hardware used in the Apollo spacecraft and ground stations appears to be lost in the mists of history, but can the original downlink hardware transmit a regular NTSC video signa…
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## [Apollo Spacecraft S Band Communication System, Part 20—Powering Up the Pre-Modulation Processor](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-20-powering-up-the-pre-modulation-processor/1754)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [27 July 2022 12:08 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-20-powering-up-the-pre-modulation-processor/1754 "2022-07-27T12:08:31Z")
After painstakingly puzzling out the multitude of control signals it requires, it’s time to carefully power up the pre-modulation processor and see if, fifty years on, it still works. Plus, a digression in…
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## [Apollo Spacecraft S Band Communication System, Part 19—Understanding the Pre-Modulation Processor](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-19-understanding-the-pre-modulation-processor/1733)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [23 July 2022 14:09 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-19-understanding-the-pre-modulation-processor/1733 "2022-07-23T14:09:32Z")
The pre-modulation processor can be thought of as the spider in the centre of the web which is the Apollo spacecraft communication system. It is responsible for assembling the downlink signal from everythi…
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## [The Song of the Dial-Up Modem](https://scanalyst.fourmilab.ch/t/the-song-of-the-dial-up-modem/1182)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 6\
**Last updated:** [26 May 2022 15:13 UTC](https://scanalyst.fourmilab.ch/t/the-song-of-the-dial-up-modem/1182 "2022-05-26T15:13:56Z")
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## [Dial-Up Modem Connection Spectrogram](https://scanalyst.fourmilab.ch/t/dial-up-modem-connection-spectrogram/1426)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [25 May 2022 13:05 UTC](https://scanalyst.fourmilab.ch/t/dial-up-modem-connection-spectrogram/1426 "2022-05-25T13:05:16Z")
An annotated description of the phases in the connection handshake appeared in an earlier conversation.
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## [“Get the Message Through”—U.S. Army Signal Corps, 1860–1976](https://scanalyst.fourmilab.ch/t/get-the-message-through-u-s-army-signal-corps-1860-1976/714)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [11 January 2022 11:26 UTC](https://scanalyst.fourmilab.ch/t/get-the-message-through-u-s-army-signal-corps-1860-1976/714 "2022-01-11T11:26:49Z")