How to properly measure OT inductance??

[R.G.]

OK, stop that.

If you learn all the tricks about your meter, there won't be any mystery left...

[woodyc]

Hey wombaticus. Many thanks for sharing your experiences with the new meter.

For output transformers, I think the most practical setup is (as S. Connor said above?) to measure them in the conditions they are used. Namely swap transformers using a reference output stage and get the "effective" primary inductance from the low end freq response. Its not a trivial thing to set up, but it really gives you the bottom line and permits relevant comparisons of transformers.

But it would certainly be nice if you could manage to do it at a single frequency, low voltage, and no tubes.

[jazbo8]

But it would certainly be nice if you could manage to do it at a single frequency, low voltage, and no tubes.

It can be done with some additional parts, see:



A good discussion can be found at: LCR meter to measure inductance of power transformer?

Jaz

[woodyc]

It can be done with some additional parts...

Thats a cool idea, but its no easier than setting up a tube stage, and there would be lingering questions about about the relevance of the result.

[jazbo8]

Thats a cool idea, but its no easier than setting up a tube stage, and there would be lingering questions about about the relevance of the result.

Yup, it isn't that straight forward either. For this test, you don't need HV or filament supplies, but still would need a scope, LV bench supply, hall/current sensor and pulse/function generator. I think it would a bit safer and quicker than a "in-circuit" test, unless you already have one built.

Jaz