With this circuit from the September 1989 issue of Radio Electronics magazine, it is possible to receive VLF band signals on a common radio, just like the signals emitted by the previous receiver.
This class B push-pull amplifier circuit with a few hundred milliwatts of power was found in an...
In the figure we have a window detector that uses only a voltage comparator. The circuit can use...
This circuit was found in an old American documentation. The operational used is of the...