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.
I am restoring a philco jr radio model 81a and I want to test the tubes however I am not familiar with the numbers
they are 77,80,42 mY tube tester manual has no such numbers
eg 4dt6,4eh7,4ej7 ............. anyone know the equivalent numbers ?