AK1 W21 Valve

Europa Socket 7-Pin C7A (Hx C, C7, C) 1933 (Codex=Leo) Top contact with cap. Used via radio/TV reception etc. Filament Vf 4 Volt / If 0.65 Ampere / Indirect / Specified voltage AC/DC Description According to Telefunken's production list, the first production of the AK1 and AK2 took place in Berlin in 1934. Only one number for AK1 and AK2 together. By 1945 the factory had built 59,255 units. In 1945/46 there were another 11 and the following year one, for a total of 59,267. For first models in the original configuration, the first delivery factor for experimental configurations, including specific circuit suggestions from the manufacturer or developer Reöhern, has a different meaning depending on the time of year, which we do not know: Finished series devices in the same or following year. Weight 55 g / 1.94 ounces Citations 5 Citations (visible only to members) Bibliography Babani, International Radiotube Encyclopedia p. 48 and 49 Paperback for tube code 1948/49 Design = Philips Universal Vademecum, electronic valves and semiconductor devices