This circuit was obtained from an American 1980s documentation. The frequency depends on the crystal and the circuit may be a PNP that reaches the generated frequency.
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
This circuit is from a 1979 documentation. The FET can be the BF245 or MPF102 and the bipolar...
Found in a book on transistors from 1954, this circuit increases the sensitivity of a...