This circuit is from a 1965 Motorola manual. It can be implemented with a common 2N2646 and a 106 Series SCR without problems. The pulse transformer has a 1: 1 turn ratio.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...