This circuit was found in an English magazine from 1977. Signal inputs and outputs must be shielded, and the circuit can be powered by battery, since its consumption is low.
This circuit was found in a 1977 Radio Handbook. Equivalent transistors can be used. The formula...
This circuit was found in a Popular Electronics from the 90's. The circuit has gained 10 to 20 dB...
The purpose of this circuit is to increase the sensitivity of a common multimeter in its voltage...