Click for larger photo.
This tester was given to me back in 2001 by a co-worker of my dad. It
has not required anything to keep it running. Researching online has
come up with little information. I believe this tester was made
sometime in the late 40s/ early 50s, and is emissions type tester. It
can test almost all older "large pin" type tubes, like 45, 24a, 6E5,
etc. It can also test several miniature type tubes, like the common
AA5's lineup. The case on mine looks pretty rough, but the unit is
otherwise solid.