This circuit covers 400 kHz to 40 MHz in three bands according to the selected coil. The double MOSFET allows equivalent, since the original is not easy to obtain.
In this circuit of a 1975 publication, a silicon transistor is used as a sensor. We can employ a...
This circuit was found in a 1978 publication. Equivalent operational amplifiers can be used. The...
The great advantage of the circuit shown in the figure is the fact that its frequency is...