Herman,
Some tubes have marks but most of what is in question has nothing. These look to be of the pre amp type.
I have many large tubes thought that I can read the numbers but am not able to test on my tester. But for now I will wait until I decide if I'm going to pursue the tube quest further. I orginally bought this mess of tubes becuase of a couple that I wanted. They came very cheap. Some of these are really cool looking. To bad I can't find a use for them.
Some tubes have marks but most of what is in question has nothing. These look to be of the pre amp type.
I have many large tubes thought that I can read the numbers but am not able to test on my tester. But for now I will wait until I decide if I'm going to pursue the tube quest further. I orginally bought this mess of tubes becuase of a couple that I wanted. They came very cheap. Some of these are really cool looking. To bad I can't find a use for them.