1 tube = one piece Ba Siemens Germany
black base thick with original label
silver box plate
hanging filament 1950's old production
postal tube telefoni
box plate
straight shape
made in Germany long life telecom tube for long distance communications
tested on tube tester Funke W19S >5mA with 150volt on anode (reference good at 2mA)
top side getter, dark flashed area
straight shape
top ceramic insulator
professional & rare tube triode for preamp stage
box 200