This amplifier with gain control was obtained in a documentation from Signetics of the 80's. Transistors are of power and operational amplifiers are not common nowadays.
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...