Found in old documentation, this circuit makes use of amplifiers of the time, uncommon today. Next to the diagram, the formula for calculating the components.
This circuit came out in a publication called Electronics Handbook of 1993. Q1 can be a 2N2222 or even...
This simple circuit allows the monitoring of both audio and RF signals. With the switch in one...
This Testa o Croce (name in Italian) was obtained from an Italian magazine in 1994. The circuit can...