We find this oscillator in a 1980s documentation. The frequency depends on the crystal and the transistor used must be able to oscillate at the desired frequency.
This circuit uses a JFET at the input to increase the impedance, and is temperature compensated...
Using L144 operational, this circuit applies to other equivalent operational. The circuit is from...
Suggested by General Electric in 1967 documentation this circuit uses an isolation transformer to...