Evacuated glass flask containing i.a. electron gun with directly heated tungsten wire cathode and a cylindrical anode. The electron gun emits a divergent electron beam, aimed at an Maltese cross of aluminum placed in the middle of the tube. The cross can be connected electrically. At the same time, light from the filament is also directed towards the cross, so that a comparison can be made between the shadows of different types that appear on the luminescent surface at the far end of the tube. Specifications.

• Unit: 150 × 100 × 60 mm
• Laser diode: 13 × 40 mm

The following phenomena can be detected with the tube: the linear propagation of the electron beam, magnetic deflection (particle nature of the electron), image distortion due to electrostatic charge, introduction to electron optics, inversion, magnification, reduction and aberration (with a Helmholtz coil) and the Broglie hypotheses.