Amplifier stage with the T411E (T411E)

The pentode tube used in this circuit has 1.5 V filament. The circuit is a voltage amplifier with the 1U5 tube.

Switched regulator (CB9153E)
This 1.2 to 32 V x 3 A regulator was found in an 80's EDN. The power components must be equipped...
Common Emitter Stage (CB4936E)
This is a typical common emitter amplifier stage configuration. The transistor can be used...
1 mA Essimeter (CB13700E)
This configuration was found in a publication for radio amateurs in 1975. It is a signal strength...