ðɪs tˈuːb wʌz dɪzˈaɪnd fɔːɹ ˈɜːli ˌeɪˈɛm slˈæʃ ˌɛfˈɛm ˌɛmdˈʌbəljˌuː slˈæʃ vˌiːˌeɪtʃˈɛf ɹˈeɪdɪˌoʊ sˈɛts ænd wʌz wˈaɪdli jˈuːzd ʌntˈɪl ðɪ ˈɛnd ʌvðə tˈuːb ˈiəɹə; ðə dˈʌbəl dˈaɪoʊd wʌz jˈuːzd fɔːɹ ˌɛfˈɛm dˌɛmədʒuːlˈeɪʃən, ðə θˈɜːd, ˌɪndᵻpˈɛndənt dˈaɪoʊd fɔːɹ ˌeɪˈɛm dɪtˈɛkʃən ænd slˈæʃ ɔːɹ ˌɔːɾəmˈæɾɪk ɡˈeɪn kəntɹˈoʊl ˌeɪdʒˌiːsˈiː.
This tube was designed for early AM/FM (MW/VHF) radio sets and was widely used until the end of the tube era; the double diode was used for FM demodulation, the third, independent diode for AM detection and/or automatic gain control (AGC).