Found in 1965 Delco Radio documentation, this circuit uses transistors from that era. Modern equivalents can be used. The characteristics of the inductor were not given.
This flasher for incandescent lamps was found in Radio Electronics from the 80's. The circuit uses...
This circuit doubles the frequency of an audio signal, thus changing its timbre. The circuit was...
We found this circuit in a Motorola publication from the 70s. The circuit can be implemented with...