• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

CV2231 (A2266, E2266)

Thank you very much for your answer. Oh sure. I was there first. I was offered a lot of these lamps at a low cost, so I decide whether to buy or not. I don’t have a tracer, and drawing curves by hand for a very long time.

I have never seen one of these valves in over 20 years collecting . Ask for a sample from the supplier , test it and plot the curves . There is probably a very good reason why there were a lot of these going cheap

316a