Found in a magazine 73 for radio amateurs, this circuit makes use of general purpose transistors and the integrated circuit is still easily found.
August 2017 - Mouser Electronics is making STMicroelectronics' Analog and Digital MEMs available in a...
We found this circuit in a 1979 French publication, but it can still be assembled today with...
Found in Texas Instruments documentation from the 1980s, this circuit applies to digital signal...