ad1 tube valvo Germany power tubes amplifier valve amp ~ ad1/350 4683 ed ebiii ww2

1 tube = one piece = 1 valve 

test 58mA ( good at 40mA ) it has few pieces of glass in the bulb ( internally )  
the tube is tested strong but has these pieces of glass internally ( please refer to pictures #3 and #4 ) 

box 81