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.
Found in an Analog Devices documentation from the 90s, this circuit uses a component of the time,...
This circuit was found in Philips documentation from 1965. No information was given about the...
This circuit was found in the June 1990 issue of Radio Electronics magazine. Integrated circuits must...