The 20-30-30 is a combined Hi-Lo angle UHF Satcom Antenna designed for installation on military vehicle roof, shelter or housing via a 4 hole "CECOM" mounting plate.

The antenna comprises two co-located elements; a circularly polarized cross-dipole and a linearly polarized broadband monopole. The two elements have separate RF feeds and by manual selection of either, full hemispheric pattern coverage is provided.

The low angle is intended for elevation angles up to about 45° and the high angle for approximately 45° to zenith.

Construction is from rugged fiberglass, foam-filled for structural integrity and prevention of moisture ingress with aluminum alloy dipole elements and base housing.

Both RF connectors are located at the base.