• 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.

Help in testing 12ax7 and 7869 tubes

Hello Everyone!

Could anyone help in testing some tubes for me? I have called all the local TV repair shops and nobody seems to have tube testers any more. I have also tried local HAM radio clubs, no response yet.

The tubes are 12ax7 and 7868 from a Fisher 400 receiver.