Found in a publication for radio amateurs from the 1980s, this circuit amplifies signals in the 60 kHz band (VLF), Winding data from the ferrite antenna are provided along with the diagram.
This is the basic operational amplifier configuration for gain 10. R2 can be changed to other...
This circuit uses a capacitor that depends on the frequency of the crystal. We found it in a 1967...
The crystal frequency of this circuit found in an American documentation is limited only by the...