This circuit that generates signals between 1.5 and 2 kHz was found in a documentation from the 90's. The capacitor C1 can be changed to obtain other frequencies.
Found in a 1968 documentation, this small amplifier was very popular at the time being used in...
This simple audio signal tracer or follower can be made with a BC548 instead of the original...
According to the 1990 documentation in which we found this circuit, the chickens must be fed at...