This circuit is from a Radio Electronics from October 1963. The transistor is a power transistor of the time, and two transformers are used. The input has 10k impedance and is powered by 12 V.
The existence of field effect transistors at the input of the integrated circuit (operational...
This circuit using current components was found in an old documentation. It is a sequential circuit...
In the figure we have a signal detector using a tunnel diode. The circuit is from a Radio...