This circuit was found in an 80's Electronic Engineering. The power supply must be symmetrical. The no value components are calculated for the desired frequency.
Using the 2N2646 this circuit was found in a Radio Electronics magazine from July 1968. The...
The purpose of this circuit found in a 1990s Popular Electronics is to increase the current...
Found a documentation for PC from 1992, this circuit is indicated for the English power grid of...