We found this circuit in December 1986, Radio Electronics magazine. It uses 3 inverters and has the frequency determined by the crystal. The power supply is 5 V.
This circuit was found in a 1973 Radio Elettronica magazine. The Italian magazine no longer...
The circuit in the figure trips with a negative transition of the input signal, its output...
This circuit was featured in the March 1972 issue of Radio Electronics magazine. It adds automatic gain...