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.
This circuit was found in an American documentation from 1968. The circuit uses transistors from that...
Found in the June 1962 Radio Electronics magazine, this circuit uses 4 transistors. The range...
We found this circuit in Popular Electronics from 1993. The circuit can be assembled with any...