This adjustable circuit from 0 to 200 nA was found in a 90's EDN. The components can still be found relatively easily, as they are CMOS.
This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL...
Found in a May 1988 Radio Electronics issue, this is a Smitt trigger that requires a symmetrical power...
The purpose of this circuit is to check the linearity of SSB amplifiers. The circuit was found in an...