I found this circuit in a documentation for radio amateurs from 1975. The FET could be the BF245. The circuit works in the range of 40, 80 and 160 meters of radio amateurs.
This bistable or flip-flop is triggered by a negative pulse applied to the collector of the...
This circuit was obtained in a 1980 publication. The transistors can be BC548 or 2N2222. The...
This circuit has its battery charged by a solar system. The circuit uses components that admit...