This circuit found in an American documentation from 1964, alters the duration of a pulse and can operate at frequencies up to 10 MHz. The transistors are from that time.
The integrated circuit used in this project is not common today, but it can be implemented with more...
Found in an American publication from 1969, this circuit can be adapted to be used as a shield....
This current meter with many scales was found in a 80s American documentation. The operational amplifier...