Found in American documentation this circuit uses transistors of the time. The circuit can be made with current components. It works as a trigger working with 600 ohm signals.
Found in a 1970 documentation, this SCR bistable can be implemented with modern equivalent SCRs. Observe...
This circuit must have its input connected to the collector of the last IF transistor of the FM...
Found in a 90s Electronic Design, this suggestion to have a higher voltage in a fixed regulator...