Found in a 1980s publication, this circuit can be modified to use modern components and operate at lower voltages. The power supply does not have to be symmetrical.
The signal itself captured by the (long) antenna serves to feed this simple experimental circuit....
This voltage level-triggered circuit was found in a 1969 Ferranti English documentation. Modern...
This amplifier makes use of a simple 12 to 30 W source, having been found in the SGS manual of...