Measuring the capacitance of an inductor or Inductors

[Possum]

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Joe, I should point out that both these pickups are probably higher than normal capacitance, PAFs in general I think are higher because of the magnet wire which really wasn't very good compared to modern wire. My pickup uses wire that is noticeably darker than PE so obviously its not a low capacitance wire either. I bookmarked that calculator and threw mine under a passing car.....

[Possum]

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Oooops, the second reading IS from a PE wound bucker, with 300 winds on the pole screw side extra. THIS one is from a pickup of about the same wind with much darker wire, so you see the capacitance on this one is the highest. Could be useful.....

[Joe Gwinn]

Oooops, the second reading IS from a PE wound bucker, with 300 winds on the pole screw side extra. THIS one is from a pickup of about the same wind with much darker wire, so you see the capacitance on this one is the highest. Could be useful.....

So, you will retrieve the pieces of the unfortunate calculator from under the passing car and nurse the calculator back to life?

[Mike Sulzer]

If your humbucker is two coils in series, the capacitance should be well under 100 pf.

[Possum]

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Not necesserily so, it all depends on tension and what kind of wire it is. PAFs have wire that isn't like anything made these days, you can clearly see in the calculator results its higher than modern PE. I'm just doing what you guys told me to and those the results I get, its all your fault

I'm not so sure drive voltage has nothing to do with it, I get different readings from my Extech from a fully charged magnet and a much weakened one, so don't see why this would be anything different.

Maybe whats messed up about this method is I am reading inductance at 1khz? I don't see Q at peak frequency in that calculator....

At least I'm getting relative measurements I can use for comparison. My calculator is banned to figuring out negative turn counts on my winder, HA! That teach it to scramble my brains. I notice we haven't heard back from Belwar, he probably exceeded brain lightspeed and blew his up, if he's as left brain challenged as I am :-)

[Mike Sulzer]

Not necesserily so, it all depends on tension and what kind of wire it is. PAFs have wire that isn't like anything made these days, you can clearly see in the calculator results its higher than modern PE. I'm just doing what you guys told me to and those the results I get, its all your fault

I'm not so sure drive voltage has nothing to do with it, I get different readings from my Extech from a fully charged magnet and a much weakened one, so don't see why this would be anything different.

Maybe whats messed up about this method is I am reading inductance at 1khz? I don't see Q at peak frequency in that calculator....

I am no expert on ancient wire, but that does seem like an awfully big difference. Also, if you are using too small an inductance value, that would make the capacitance too big using this method. But I doubt that you are off by that much.

This brings up the question: what is Joe's method? There are two, sort of. The one you are using, and the other, what I have called Joe's suggested method, which uses multiple external capacitors. It does not need an inductance value; in effect, it uses multiple measurements with different capacitor values to determine the inductance, but you never need to actually measure it.

[Possum]

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The old magnet wire was VERY different. The insulation is nothing like what is used now, it was made of different materials, the modern stuff isn't the same. Its real obvious to me how different the old stuff is, when I remove all the parts of a PAF, the magnet, and all steel parts and put it into a near identical wound modern wire coil the pickup is way brighter than the old coils. I have read posts by old engineers talking about the old magnet wire saying it was total crap compared to modern. I'm sure the copper was also not as pure as what they are using now. I know that the steel we use now is "better" than the old steel also, from the metallurgist I talk to.

Does Joe's version.2 method involve a calculator with alien symbols and quantum mystical mental states of the left brain? Hope not.....

[Mike Sulzer]

The old magnet wire was VERY different. The insulation is nothing like what is used now, it was made of different materials, the modern stuff isn't the same. Its real obvious to me how different the old stuff is, when I remove all the parts of a PAF, the magnet, and all steel parts and put it into a near identical wound modern wire coil the pickup is way brighter than the old coils. I have read posts by old engineers talking about the old magnet wire saying it was total crap compared to modern. I'm sure the copper was also not as pure as what they are using now. I know that the steel we use now is "better" than the old steel also, from the metallurgist I talk to.

Does Joe's version.2 method involve a calculator with alien symbols and quantum mystical mental states of the left brain? Hope not.....

I wonder also if there has been some deterioration in the original pickups that has caused a loss of brightness.

Yes, version.2 is more complicated to use.

[Possum]

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The '63 I measured uses poly wire which lasts forever usually, I have a '62 with PE but its completely disassembled, maybe I'll put it back together and measure that one to see if there's any difference, my guess is that it will have higher capacitance than the '63

[Joe Gwinn]

Does Joe's version.2 method involve a calculator with alien symbols and quantum mystical mental states of the left brain? Hope not.....

Umm. Absolutely. Scientific notation.

And phasors too: Phasor (sine waves) - Wikipedia, with pictures even.

The good news is that this is the door to a space orthogonal to real.

[Possum]

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That is THE most terrifying web page I've ever seen Is there a web page calculator for it?

[David Schwab]

And phasors too: Phasor (sine waves) - Wikipedia, with pictures even.

(In Homer voice) Mmmmmmm... pictures....



Just stare at it for a while... it wont hurt a bit...

The good news is that this is the door to a space orthogonal to real.

The suffering of pious people = The arrogance of their God “divided by” The ostentatious generosity of their God?

[Possum]

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I see........God, the one before that is a winder cam....

[David Schwab]

I see........God, the one before that is a winder cam....

That was what's know as "the orthogonal space poem".

[LtKojak]

Is it me, or everybody 'round here seem to have emptied their meds supplies...?