The company's roots can be traced back to then Loreto F. de Hemedes, Inc., owned by Robert Uncle Bob Stewart, an American war correspondent. The company started with the launching of its first AM radio station in Manila through Radio Broadcasting Station, DZBB. It went on air on March 1, 1950 using the frequency of 580 kHz of the AM band, broadcasting from the Calvo Building in Escolta, Manila. Its early radio coverage highlights were the crash of President Ramon Magsaysay's plane in Mount Manunggal; the eruption of Mount Hibok-Hibok and various local elections in the Philippines. DZBB became the first radio station in the Philippines to use telephones for live interviews.