In which direction is the maximum radiation from a VHF/UHF “halo” antenna?

A halo antenna is essentially a half-wave dipole that has been bent into a circle, leaving a small gap between the ends. Bending the element alters its radiation pattern from the traditional bidirectional figure-eight of a straight dipole into a nearly circular shape. As a result, the maximum radiation occurs omnidirectionally in the same plane as the halo itself. This makes it highly popular for VHF/UHF mobile work where horizontal polarization is required (like SSB or CW), but the vehicle's constant change of direction demands an omnidirectional pattern.