Model: 3X2500A3 (also stamped 8161). – Type: Air-cooled power triode, glass envelope with integral copper anode radiator. – Glass envelope clear and intact — no cracks, no visible vacuum loss. – Era: Mid-1940s (tube line introduced 1945).
Model: 3X2500A3 (also stamped 8161). – Type: Air-cooled power triode, glass envelope with integral copper anode radiator. – Glass envelope clear and intact — no cracks, no visible vacuum loss. – Era: Mid-1940s (tube line introduced 1945).