In the figure we have the way to obtain 500 gain from a FET. FETs can be BF245 or MPF102. The circuit is from the 1977 National Semiconductor FET Data Book. Power supply depends on the application.
This circuit was used to reinforce radio signals for listening on the phone, making it possible to listen...
This synthesizer circuit was found in a Radio Electronics magazine from May 1983. The circuit uses...
The circuit that gave rise to this configuration was found in a magazine of the 1980s with the...