This circuit was found in an Electronic Experimenter Handbook from the 90's. The coil can be formed by 4 turns of wire 28 with 0.5 cm diameter without core for the FM band.
We found this circuit in an old documentation from the 70s. The sensor is an LDR that must be...
This circuit with junction field effect transistors was found in documentation from the 1980s. The...
Common general purpose silicon diodes when direct biased provide a voltage fall of about 0.6 to...