CuriousMarc, kens, and crew have been recreating the up & downlinks for Apollo using vintage NASA hardware. They recently were able to send commands to their AG

CuriousMarc, kens, and crew have been recreating the up & downlinks for Apollo using vintage NASA hardware. They recently were able to send commands to their AGC[0][1] remotely. No encryption used, just a hefty investment in RF engineering. The techniques were probably closely held at the time to prevent Soviet interference, but these days you can just download the circuit diagram PDFs. [0] Simulated, since the owner of the original AGC wanted it back. [1] https://www.youtube.com/watch?v=tBy1j9cTYKc https://www.youtube.com/watch?v=tBy1j9cTYKc