We found this circuit in the June 1987 issue of Radio Electronics magazine. With it, it is possible to receive signals from the bands determined by the crystals in a common medium wave receiver.
In the figure we have the way to adjust the output null of an operational. The configuration...
The circuit shown was found in the 1994 National Semiconductor's Linear Application Handbook. The...
This article is old, from 1994. But, for those who have an old PC and want to use a joystick from...