WEBVTT

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This object has 4 halved discs and 3 solid discs ...

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With the shape of an ellipse, the variable capacity that is related to the angle of rotation is linearized!

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It is the air that serves as insulator for this condenser!

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When the half discs are 100% opposite: you get the maximum capacity!

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And minimal when the opposite but check!

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At least: 11.5 pF

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Capacity increases when overlap increases ...

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For a maximum of 57 pF, a ratio of 1 to almost 4!

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We can not reach 0 because the centers of the discs remain opposite!

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What is the origin of this component?

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This variable capacitor used to select the frequency of the tuner (radio station TSF at the beginning of the twentieth century!)

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The tuning was related to the selected resonant capacity with a coil! Regular tuning was required! Air humid ...