This 1000: 1 voltage-controlled filter circuit was found in an Electronics Today International in a 1980s edition. The circuit is based on components of the time.
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
This circuit was found in a 1980s documentation. It is intended for remote vibration monitoring...
This headphone amplifier has good gain and high input impedance. The circuit is from Electronics Now and...