[en] The effectiveness of an axial RF current, whose frequency is not much smaller than the ion cyclotron frequency, on the dynamic shear stabilization of the hydromagnetic instability in low-beta plasmas was analyzed, using the simple model of a uniform plasma column with infinite conductivity. Attention was limited to the case of the m = 1 kink model with long wave lengths. The Mathieu equation, in which the effect of the ion cyclotron motion is taken into account, was derived. It is shown that the dynamic shear stabilization is still effective, even if the frequency of the applied RF current is of the order of the ion cyclotron frequency, which is considerably higher than the frequencies believed to be available in the previous analyses