Radio experimenters often need a variable capacitor to tune their circuits, as the saying goes, for maximum smoke. In decades past these were readily available from almost any scrap radio, but the ...

If you’ve seen a big air-variable capacitor, you may have noticed that some of the plates may have slots cut into them. Why? [Mr Carlson] has the answer in the video below. The short answer: ...

The first British commercially available high-vacuum variable capacitors have been announced by the English Electric Valve Co. So 64 years ago, started a story in Electronics Weekly’s edition of March ...