a magnetic deflector of the saddle - saddle type , for a trichromatic tube protected by a shield , with in - line guns and round - luminophor type screen , is designed to function with a saddle - torus type of magnetic deflector . the invention uses a saddle - saddle type of deflector in which the front leading - out wires have been reduced and the rear leading - out wires are laid flat . furthermore , the ferrite piece is extended by a ring which surrounds the rear leading - out wires and is magneticlaly closed by a ferrite ring bearing a quadrupole coil powered by a parabolic current . the intention can be applied to round - luminiphor trichromatic tubes fitted with an external shield .