ɪn ˈɜːli nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi sˈɪks, ɐ nˈuː ænd mˈoːɹ pˈaʊɚfəl mˈiːdiəmwˈeɪv tɹænsmˈɪɾɚ sˈaɪɾᵻd nˌɪɹ sˈoʊfiə wʌz dʒˈɔɪnd baɪ ɐdˈɪʃənəl tɹænsmˈɪɾɪŋ stˈeɪʃənz æt stˈɑːɹɹə zˈæɡoːɹə ænd vˈɑːɹnə, ɡˈɪvɪŋ bʌlɡˈɛɹiən nˈæʃənəl ɹˈeɪdɪˌoʊ kˈʌntɹɪwˌaɪd kˈʌvɚɹɪdʒ, ænd ˌɔn twˈɛnti wˈʌn mˈeɪ ʌv ðæt jˈɪɹ ɹˈeɪdɪˌoʊ sˈɑːfiːdʒə bɪɡˈæn bɹˈɔːdkæstɪŋ ˌɪntɚnˈæʃənəli.
In early 1936, a new and more powerful medium-wave transmitter sited near Sofia was joined by additional transmitting stations at Stara Zagora and Varna, giving Bulgarian National Radio countrywide coverage, and on 21 May of that year Radio Sofija began broadcasting internationally.