If you are thoroughly grounded — no pun intended — in LC circuits, you probably won’t learn anything new. However, the animations are worth watching, just to admire them, if nothing else.

Glen Chenier’s blog I reposted yesterday got me thinking about other LC measurement techniques, including an inductance checker I built about 40 years ago and haven't used in nearly as long. The ...

With the circuit shown, values of C1 and C2 should be chosen so that the maximum LC oscillator frequency is about 500 kHz. Frequency measurements are made for 32.5 ms.

It would be an LC oscillator whose frequency is changed by the variable capacitance of one or more varactors. A digital method of modulating a PLL is to rapidly change the divider value.