The indicator for this circuit is a 0 to 1 mA milliammeter. The operational is from the 70s, when the circuit was published. Modern equivalent can be used.
This interesting circuit that generates delayed pulses was found in the September 1992 issue of...
We found this amplifier with 50 MΩ input resistance in the May 1989 Radio Electronics magazine. The...
This monostable is triggered by the falling edge of the input signal, just adding an inverter...