This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
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...