With this circuit it is possible to vary the resistance by adjusting the mark/space reaction of the 555. The circuit was found in the November 1989 Radio Electronics magazine.
We found this transistorized AM receiver of the regenerative type of excellent quality in a...
This continuity tester for low resistances was found in an English magazine from 1978. The circuit...
Found in American documentation from the 1980s, this circuit rejects strong MW stations that may...