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.
This series sensor circuit is from 1995 Popular Electronics. The circuit can use any SCR and the...
This reinforcing stages from a 1960s documentation. No information is given about the transformer...
This circuit was obtained from an American 1980s documentation. The frequency depends on the...