Found in an American documentation from the 90s, this circuit has a configuration that has been extensively explored in other articles on this site. The FET can be the MPF102 or equivalent.
Found in a 1960 Sylvania manual, this circuit can be implemented with a modern equivalent...
This configuration, already presented in other points of this section and website, is of a...
We found this precise crystal oscillator for the 144 MHz band, depending on the crystal used. The...