Found in an American publication from the 1980s, this circuit can be found in commercial sound equipment of the time. The list with the component values is given next to the diagram.
In the figure we have a Texas Instruments circuit for TTL interfacing using discrete transistors. The two...
This circuit was found in Radio Electronics magazine from June 1963. The range is small and the...
The project presented in a 2009 documentation is intended for radio amateurs operating in the...