This circuit with power MOSFETs was found in a 1980s Siliconix documentation. Equivalent MOSFETs can be used, as well as other transistors. Note the symmetric power supply.
This unity gain circuit was found in the February 1995 Electronics Now magazine. The frequency is 10 kHz,...
Found in a 1967 Electronic Design, this transistorized circuit compresses and then expands a pulse....
This TTL pulse stretcher or stretcher was found in a 90's EDN. The time constant R x C1 determines...