This circuit is a four-quadrant multiplier using an LM3900. The circuit was found in the July 1988 Radio Electronics magazine.
Found in American documentation from the 90s, this CMOS circuit detects the source of a signal and can...
I found this circuit in an old English magazine from 1981, but it can still be assembled with some...
This circuit was obtained from a 1969 Electronic Design. Transistors admit modern equivalents. The frequency...