they apparently made 42 of these different radio cards back in the day, for stations in Kanto, Kansai and Tokai, across FM, AM and Shortwave radio frequencies. The system even won a Good Design Award in 1988 https://www.g-mark.org/award/describe/14593
you can read a bit more about it, and see more up-close photos on this store page, it’s a fascinating little artifact of ‘80s Japan http://web.archive.org/web/20200407015941/https://palette.ocnk.net/product/1124 (Internet Archive link because who knows how permanent the listing will be!)
now the really fun part is I only know these exist because Sony, almost exactly twenty years later, went on to pay homage to them by using this as the basis for a bunch of PSP internet radio players http://web.archive.org/web/20120620003046/http://www.playstation.com/psp-app/radio/en/clip.html
@ticky it is but it works really well 😄
@noiob that’s a funny thing for a PSP to be doing but I understand