This circuit was obtained in a 1964 Electronic Design. The transistors are from the era and the instrument is 100 uA full-scale.
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...