This is the circuit of a modified Heathkit kit. The circuit was found in a Radio Electronics from December 1965. The author of the circuit included improvements to the original circuit.
This circuit was obtained from a Radio & Electronics Constructor from March 1976. The magazine no...
This buffered version of the previous circuit appeared in an article in the September 1989 Radio...
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...