We found this circuit in an old documentation for radio amateurs. The circuit uses an analog indicator. The characteristics of the coils are given next to the diagram.
This high-gain circuit was found in an American publication from the 1990s. The circuit can use...
This circuit automatically controls the degree of illumination. As the circuit is from 2001, it...
This circuit was found in a Radio Electronics from April 1990. The circuit has 5 equalization...