This is a Prototype Precision 10-12 Tube Tester that I calibrated and is fully functional. I believe this was a predecessor tube tester to the 10-12 that was never produced. The rectifiers are solid state. I noticed that there is a Gas switch that is not connected. It looks like it was planned to have a Gas test, but it was not implemented.
I did a minimum restoration since the tube tester was clean and didn’t seem to have much use. When I tested some tubes, the results were as expected.
I got this tube tester off eBay and have no idea of its history. It was very nicely constructed using good prototype practices in a clear plexiglass case.
I had to use use the settings from the 10-12 tube tester to test tubes because there is no roll chart. I have posted the 10-12 tube tester Manual and Test Data here Tube Tester Manuals.
The Prototype Precision 10-12 Tube Tester is $250 plus shipping to the lower 48 states only because of the weight.
Contact Me if you have a tube tester you want calibrated.
