This sensitive two-transistor circuit was found in the June 1965 Radio Electronics magazine. The circuit has low drift and uses an analog instrument. The input resistance is high.
This circuit is used in transceivers, enabling input selection by diode switching through polarity...
This configuration was found in an American publication from the 90s. Operators admit equivalents just...
This circuit was found in an Italian magazine Elettronica Prática of 1977. The transistors can be...