From GTA BOOM: “The new party and music-themed Cayo Perico brings heaps of new content along with a new type of collectible that rewards you handsomely in the form of $GTA, RP, and a new radio station called Still Slipping Los Santos. There are ten radio antennas scattered throughout Los Santos.”
Source: N4G PC All 10 Antenna Locations For Cayo Perico Heist In GTA Online