OK this reminds me of a book by Harry Harrison, the second in the Deathworld series. (Bear with me.) The general scene is a galaxy in which high-tech humans have spread out and colonized various planets, spaceships, space suits, etc. Our hero Jason is somehow stranded on what is basically a Medieval planet, in which humans have forgotten their technology and political advancements and were under the thumb of feudalism.
He uses his knowledge to (IIRC) build a Leyden jar, to demonstrate his “magical powers” by zapping “unbelievers.” He allies with a local feudal lord “Hertug” and builds a prayer-wheel type device that outputs a series of zaps and pops that spell out “Hooray for Hertug” but to our ears would be an SOS. Any passing ships might pick up on that crude radio signal. The local serfs are set to work, cranking on that thing 24/7. Eventually he is rescued by his GF, who was flying in a spaceship nearby, looking for him and picked up on the signal.
I would have guessed that the Church, specifically local bishops and archbishops would have a lot of the stations and doing lots of religious programming. I’d even go so far as to think they’d do their absolute best to monopolize the technology.
In a mostly pre-literate age, something like radio would be a HUGE tool for manipulating the masses and even the nobility.
“Greetings villeins, and welcome to Trade and Barter Time. Peter over in Coddlesthorpe has a nice fat sheep, slightly lame in the left foreleg, which he will exchange for a hogshead of ale or other congenial spirit. And Agnes of Arundel is offering what she calls “a good tyme” for tuppence, or best offer.
We’ll be back with more after this exhortation from the lord of the manor.”
