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.
Bipolar transistors are types of general use like BC548, while the power MOSFET can be of any type...
The output voltage of the circuit shown in the figure is approximately 7.0 V for a 15 V supply...
Of course, other frequencies can be generated by changing the components. The circuit generates a...