I think these may have been discussed before on the forum but they fit in here well enough as a colour/background element of any post-apocalypse scenario.
Specifically I am talking about two ideas to get long-range comms back after the breakdown.
The first is a concept still in use by ham radio operators so is very much a proven idea. Earth-Moon-Earth communications, basically you aim your microwave transmitter at the Moon and someone somewhere else in the world can pick it up with their microwave receiver.
Quite a bit easier than trying to get a hold of working comms satellites, finding a suitable launch vehicle, fuelling said launch vehicle and then getting the satellite into orbit.
https://en.wikipedia.org/wiki/Earth%..._communication
The second is a little more difficult and has a limited life span of a year or two. Difficult because it does require a rocket to deliver a package into orbit and the package itself needs some thought put into how it will deliver its contents but the concept itself is incredibly simple.
Essentially, a collection of short lengths of copper wire, placed in orbit, function like a giant antenna. It was a serious consideration in the 1950s when North America and Western Europe had either ionospheric radio or undersea cable as their only means of long-range communication with each other.
But their are issues with seeding near-Earth orbit with 20kg of copper wire, aside from finding a suitable rocket to get it there.
https://www.wired.com/2013/08/project-west-ford/
https://en.wikipedia.org/wiki/Project_West_Ford
Both concepts could be attractive solutions for rapidly re-establishing communication in a world that is very dependent on satellites for long-range comms these days.