The Rikstone Tube Tester is based on a simple tester published
in a Polish radio amateur magazine in 50's. I have modified the original circuit  for the tubes I use mostly i.e. 12AX7 (ECC83), EL84 and EL34. For more information see the detailed description.

See also the Polish (Polish only) article.
Schematic

Schematic (More advanced)
User's Guide (In Finnish only)