Antenna tuner (CB7459E)

Found in a QST from the 90's this circuit is suitable for the medium and short-wave range.

| Clique na imagem para ampliar |

Photosensor for robot follows the line (CB26018E)
This simple robot or motor control circuit using a photocell as a sensor was found in the magazine...
Light Modulator 741 (CB16810E)
This circuit uses an operational amplifier to modulate the light emitted by an LED with audio...
Transistor Monostable (CB19361E)
Equivalent transistors, such as the BC548, can be used in this circuit that we find in...