This circuit was found in a 1945 publication. The circuit was stated to be part of a walk talkie. Note that, as it is a portable assembly, it was powered by batteries. The jack was for microphone insertion.
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...