Hi, I'm trying to calculated the inductance of different coils using this formula with the results from resonant circuits:

So, instead I'm using this circuit (substituting the proposed "search coil" with my own coils):

I can see in the oscilloscope how the coil resonates with the 1n capacitor, and I can get the inductance using the values of the resonance frequency and the capacitor. However, when I change the capacitor for another value, and do the calculations again to check if the formula is working, I get a complete different result; which rather suggests that something went wrong... can you see what it is?

Also tried it with a colpitts oscillator, and I also get a completely different set of values.

What would be the easiest circuit to see the resonance of a capacitor and a coil, repeatedly on the oscilloscope, and which I could use to calculate the inductance?

Thanks,

\(L = \frac{1}{4 \times \pi^{2} \times f^{2}_{r} \times C}\)

The problem is: the coils are too small for the experiment proposed here: Inductor-capacitor "tank" circuit, where they propose this circuit; as I can't see the result on my analog oscilloscope.

So, instead I'm using this circuit (substituting the proposed "search coil" with my own coils):

I can see in the oscilloscope how the coil resonates with the 1n capacitor, and I can get the inductance using the values of the resonance frequency and the capacitor. However, when I change the capacitor for another value, and do the calculations again to check if the formula is working, I get a complete different result; which rather suggests that something went wrong... can you see what it is?

Also tried it with a colpitts oscillator, and I also get a completely different set of values.

What would be the easiest circuit to see the resonance of a capacitor and a coil, repeatedly on the oscilloscope, and which I could use to calculate the inductance?

Thanks,

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