Had an idea for a faction to put in a project zomboid game with custom NPCs and such once such systems are in place to do so:
The Rebel Radio Collective (RRC for short)
Before the infection, most of these people were local ham radio enthusiasts, but once stuff started going south they quickly became the go-to long-distance communications specialists of knox country. Operating out of the former KNN broadcast tower, an abandoned military base, and a handful of other fortified positions with supplies and radios at the ready, they organize communications for all sorts of other groups around the region, as well as setting up in-person meetings for different groups.
They also broadcast updates on areas to avoid due to high zombie populations and the movement of hordes, and whenever there's nothing of that sort to be sending out over the airwaves, well, they have an expansive catalog of recorded music to play instead for all who will tune in.
Their initial introduction comes around a month after the initial infection, with a broadcast on KNN's frequency:
-nyone hear me? This thing still work?
Hmm, no response. Maybe it'll take some tinkering to get it to go two ways.
Wait, getting something. Anybody out there? Hello?
Not sure how it'd get to this point from there story-wise, but within a month of that it'd be broadcasts like this in between sections of music being played:
"Hey everybody out there, we've got your latest horde news: Looks like there's a few big groups heading out of Louisville, going in the general direction of West Point and Rosewood. Avoid the woods in that area, they're not exactly following the roads. And this probably doesn't need to be said at this point, but for those of you sheltered in areas they're heading for, make sure to shore up your defenses. Wouldn't want you to join the masses out there. With that out of the way, we're back to your regularly scheduled tunes!"