Abstract The problem considers the effect of an angular d.c. magnetic field on the radiation of a uniform magnetic ring source (slot antenna) situated on the surface of an infinitely long metal cylinder covered by a plasma sheath. It is observed that, in a relatively high density plasma (ω p /ω>1), the application of a static magnetic field improves the transmission of electromagnetic waves. However, it is shown in this paper that, in a low density plasma for which ω/ p /ω 1. When a static magnetic field is present, the increas...