This interesting circuit for analog TV selects the first line of a frame. The circuit was found in a 1967 Electronic Design. A modern equivalent transistor can be tried.
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...
Originally, this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
The previously mentioned versions of monostable multivibrators in this section are not...