This circuit is from an old documentation, making use of an operational of the time. The circuit can be adapted to use modern components. The power supply must be symmetrical.
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...