Found in a Popular Electronics from the 90s, this circuit is intended to measure the harmonic distortion of an audio signal. The circuit can be tuned between 970 and 1030 Hz.
We found this circuit in the Electronics Experimenter Handbook 1983 edition. The circuit uses...
This little-known regulator today was found in a Radio Electronics circuit from December 1978. The...
This circuit was obtained in a 1982 Maplin magazine. The circuit can be applied to equivalent power...