We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994. The circuit can be adapted to use other operational amplifiers and the power supply must be symmetrical.
We found this circuit in an American 1980s documentation. The transistors can be equivalent as BC548...
We found this circuit in an old publication on oscilloscopes. Its purpose is to observe the Ie /...
This circuit, called Kames Dandy, can mix signals from a wide range of frequencies and is...