The 6AL5 is a 7-pin miniature dual diode engineered for low-power detection, FM ratio detector/discriminator circuits, TV video detector, and DC restorer stages. Introduced in the post-war era, it features separate cathode leads for each diode section to provide circuit flexibility and excellent high-frequency isolation. Operates on a 6.3V heater and fits standard 7-pin miniature sockets. European equivalent is EB91 / EAA91. Available NOS and tested used.