  We show that global Strichartz estimates for magnetic Dirac operators
generally fails, if the potentials do not decay fast enough at infinity. In
order to prove this, we construct some explicit examples of homogeneous
magnetic potentials with less than Coulomb decay, i. e. with homogeneity-degree
more than -1, such that the magnetic field points to a fixed direction, which
does not depend on $x\in \mathbb{R}^3$.
