In the last edition of Don’t Fear the Filter, we built up two examples of the simplest and most-used active filter of all time: the two-pole Sallen-Key lowpass. This time, we’re going to put two of ...

This audio noise filter circuit is a bandpass filter for audio frequency band. It filters unwanted signals that are lower or higher than the audio frequencies. It has 2 filters: a low pass filter and ...

Noel Maginnity is a consultant in Carterton, New Zealand. An alternative audio program input is often required at a medium-wave transmission site. During STL maintenance or if the STL fails, it is ...

Toroidal inductors can be used in passive-filter and equalizer circuits in the VHF range. Although SAW filters have taken over many bandpass filter applications, LC low-pass and high-pass filters are ...

Unless you hold a First Degree RF Wizard rating, chances are good that coax stubs seem a bit baffling to you. They look for all the world like short circuits or open circuits, and yet work their magic ...