Uploaded April 2023 | Updated September 2026, 2 weeks ago

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Nothing is more emblematic of the Apollo communications than the Quindar tones, which you hear at the beginning and end of each transmission. In this episode, we hack a cheap commercial microphone to bring it up to NASA standards by adding the tones. After explaining what they do, of course.

Apollo Comms Playlist: youtube.com/watch?v=v49ucdZcx9s&list=PL-_93BVApb58SXL-BCv4rVHL-8GuC2WGb

Project notes and schematics: curiousmarc.com/space/quindar-tone-generator

Links to doc:
curiousmarc.com/space/apollo-s-band-communications
virtualagc.github.io/virtualagc/QuestForInfo.html
ibiblio.org/apollo

Music Credit: Crinoline Dreams by Kevin MacLeod

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