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.
Any power MOSFET that supports the current of the controlled stepper motor can be used on this...
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This circuit was found in a Popular Electronics of the 1990s. The sensor is a rotating mechanical...