We found this circuit in an American documentation from 1947. The circuit uses 5 tubes and has a feature to keep the tube filaments preheated.
PIC16F15386 Family with CIPs Uses MPLAB® Code Configurator for Quick Development The PIC16F15386...
This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are...
This configuration was found in a 1988 documentation. It is a touch lift drive system. The circuit...