This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be done based on transistors with known gains.
This good gain antenna up to 30 MHz was found in an American 1990s documentation. The circuit can be...
This circuit was found in the Analog Devices component manual, providing a negative voltage of 2.5 V...
With the appropriate choice of C1 and C2 it is possible to divide the frequency of a rectangular 3 V...