Indicated for adjustment in transmitters for the 11-meter band, this circuit with analog meter was found in the Radio Electronics magazine of January 1978. The circuit does not use a power supply.
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....