Found in 90's Electronic Engineering this circuit can be used to measure phase angles between two signals from 0 to 180 degrees. The components used admit modern equivalents.
This fuzz distortion circuit was found in old RCA documentation. Equivalent transistors may be...
This circuit with transistors of the time was found in the magazine Radio Electroinics of June of...
Several versions of this circuit can be found on this website. This makes use of FETs that can...