# Apollo Spacecraft S Band Communication System, Part 4

**URL:** <https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-4/455>\
**Category:** Continuity\
**Tags:** radio, microwaves, apollo, space\
**Created:** [27 November 2021 12:54 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-4/455 "2021-11-27T12:54:58Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![johnwalker](https://scanalyst.fourmilab.ch/user_avatar/scanalyst.fourmilab.ch/johnwalker/32/17415_2.png) [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Post date:** [27 November 2021 12:54 UTC](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-4/455/1 "2021-11-27T12:54:59Z")

</div>

[![](https://scanalyst.fourmilab.ch/uploads/default/original/2X/c/c106af76331c3078e72e5dd67fd23085bb80b443.jpeg "Apollo Comms Part 4: Transponder power up preparation, and more original equipment found.") ](https://www.youtube.com/watch?v=X0GhLIJdNhM)

Having examined the system architecture and hardware components in parts [1](https://www.fourmilab.ch/scanalyzer/archives/2021/09/apollo-spacecraft-s-band-communication-system-part-1.html), [2](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-2/68), and [3](https://scanalyst.fourmilab.ch/t/apollo-spacecraft-s-band-communication-system-part-3/315), now it’s time to see if this fifty year old gear can be brought back to life. But, before hooking it up to 120 volt power, you’be better be sure you know where to connect it. One thing _is_ sure—it’s unwise to blindly trust half century old schematics without checking for yourself.