This circuit was found in the April 1983 issue of Radio Electronics magazine. Its purpose is to couple an antenna to two receivers without problems with coupling losses.
In the figure we have an improved method of varying the voltage of a 7812 regulator. The circuit is...
This 5-range current measurement circuit was found in the September 1989 issue of Radio...
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....