The inside of classic radios holds wonders that the sterile chips and SMD components of today’s circuits can’t hold a candle to. Chunky resistors and capacitors, vacuum tubes with cathodes aglow, and ...

How do you implement a variable capacitor these days? Mechanical caps are out. That leaves varactors, which work fine but require higher voltages that often are not available, and their response is ...

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 ...

Marked: "Dayton Fan & Motor Co. / Dayton, Ohio, U.S.A. / Day-Fan". A Variable capacitor with six fixed plates and six movable plates. Arrangement of plates permits interleaving of sets of three each, ...

Variable capacitors may be useful, but the air gap that provides their capacitance is their greatest weakness. Rather than deal with the poor dielectric properties of air, some high-end variable ...