[Scott Harden] has been working through a design for a variable inductor to use as a PTO, or permeability tuned oscillator. What you see above is the most recent fruit of these efforts. The variable ...

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 ...

Editor’s note: PhD candidate, Seyyed Hossein Pishgar approached me with this paper, which I believe has some unique and creative circuitry and architectures. I have ...

For the PDF version of this article, click here. Click to read part I and part III of this article. In part one of this article (see “SPICE Analog Behavioral Modeling of Variable Passives,” March 2005 ...