We found this circuit in a 70s Electronic Design documentation. The circuit uses general-purpose transistors from the time. Linearity is better than 0.25%.
This simple expandable circuit was obtained from a Popular Electronics from the 80's. The supply...
The frequency of the LC resonant circuit must be the same as that of the crystal and the JFET...
This circuit was obtained in a Popular Electronics of 1991. The magazine no longer exists, but the...