I’d love some assistance in finding such a source, if one exists.
I’m interested in the broadcast radius of several local commercial and public broadcasting stations. Googling does reveal maps for stations kind enough to offer such information, but this is a tad hit-and-miss. I’m thinking of, say, individual images that, in a bygone era, might have been presented as overlays on a hanging map. Does this sort of thing exist in a publicly-accessible format?