This circuit is from a Radio Electronics from March 1970. The crystal depends on the frequency at which the signal is to be captured and the resonant circuit determines the tuned band.
This circuit was obtained in a 90s American documentation. The integrated circuit used is uncommon...
This circuit was obtained in a 1980 English magazine, but it can be easily assembled today, since...
This configuration is used to display the characteristic curve of a diode in the virtual...