• 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.

testing tubes for shorts

came across this circut....looks simple enough. if one were to add mil=amp meeter connection points in series with the pilot lights.....would it allow to measure for leaks as well? any other diy circuts out there for shorts and leaks?


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Yes, that is a better idea. i did the same thing to. used it in my homebrew tube tester.

My circuit consists of A 230volt neon tube. whit a 100n capacitor in series shunted whit 4M7. fed off 205Vac..
the capacitor is to stop the tube from conducting current, acting as a half wave rectifier.

works really well. flickers under 2M resistance. and glows brightly under 500k.
already found tubes whit shorted grids.. cathode shorts and a lot more faults.

my tester has a test switch whit 10 positions 2-9 test leakage/shorts and position 10 test anode current

Hi v4lve lover

Do you have a schematic how you did that?
I’m busy building a tester but i still getting lost how to
Make it test it properly for shorts & leakage

Do you measure from the heater to all other elements
Or from ground?
And if you measure with 205vac can you burn a tube when connected to the heater?