The phone call was routed via normal telephone cable to Houston Mission Control
Then they went to the satellite uplink, and finally to the radio the astronauts could hear on the Moon.
There is nothing magical about it.
Actual uncut footage of the call, including a clear 7 second delay after Nixon stops and Neil begins
https://youtu.be/VLyJ9FHDO-c?t=104Because it was recorded on Earth, there is no corresponding delay when Nixon starts talking again
Anybody who's spoken on a Zoom call knows this delay
