testing tubes for shorts

[speakerfritz]

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?

 

[Rundmaus]

6V will be too low to measure leak currents, as the leak resistances are usually still in the high k-ohm range...

Greetings,
Andreas

 

[Osvaldo de Banfield]

Inplace of pilot lamps, U can use neon lamps in series with a high value resistor and higher voltage outputs at transformer winding to see leakages. See the radiotron's book for some circuits and considerations.

 

[speakerfritz]

Ok, so maybe 180v and some of those neon bulbs

 

[v4lve lover]

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

cheers.
V4lve

 

[Davo013]

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?