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.
The filter shown in the figure, suggested by Motorola, operates at a cut-off frequency of 1 kHz,...
This circuit uses an unusual operational amplifier nowadays and has a very low consumption. The...
In this circuit R1 has 2M5, R2 and R3 are 5M obtaining a detection current for the diode of 0.5...