Stato:USA (Stati Uniti d'America) Produttore: Common type USA tube/semicond. Tipo: Convertitrice pentagriglia (Eptodo) Frequency converter Controllo (mu) Identico a 2A7 = Ut-2A7 = ER2A7 = CV787 = PH2A7 = Ut2A7 = NU-2A7 Valvole simili Other shape (e.g. bulb type): 2A7S ; G-2A7-S Other class quality (otherwise equal): NU-2A7S Heater different: 6A7 Prime serie 1933 Radios von gestern, 2. Auflage page 231 (Base for 2A7 and 6D7)started >200 models Prime informazioni Apr.1933 : 70 Years of Radiotubes and V. Mar.1933 : The AWA Journal Vol. 7, 1992 Evoluzioni 6A8 6A8G