The story
The station was founded by Imran Amir, Mursid Rustam, Malik Sjafei, Bambang Wahyudi, and Tri Tunggal. During the late 1960s, Prambors is the nickname one of the gangs from Menteng, in downtown Jakarta. Prambors is an abbreviation of Prambanan, Mendut, Borobudur, dan sekitarnya (Prambanan, Mendut, Borobudur and the surroundings), the name of several streets in Menteng, Central Jakarta. Starting from being amateur station, Prambors changed its name commercially due to government laws, with the name PT Radio Prambors. The radio network was launched in 1970 and incorporated in 1971 as Prambors Rasisonia — Rasisonia itself stands for Radio Siaran Sosial Niaga (Social Commercial Broadcast Radio).
From Wikipedia’s article on Prambors FM, shared under CC BY-SA 4.0.4