This circuit was found in a 1980s documentation for amateur radio. The circuit makes use of components of the era, but modern equivalents can be used.
This rather sophisticated circuit does not recognize false tones, such as harmonics, and can be...
This circuit is intended for testing circuits with RIAA equalization. We found this configuration in a 1977...
We found this two stage transistor amplifier circuit using RC coupling in a magazine published in...