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.
This circuit is from 1983 documentation. The author shows us an experimental circuit of a siren...
This simple circuit indicates whether at a point in the wiring of a car 12 V is present. The clip...
This oscillator employs a Motorola operational amplifier common in the 70s. We can implement the...