The 21-50-37 is a vertically polarized, omni-directional antenna, compatible with high power airborne radios operating within the 100 to 500 MHz frequency range. This antenna can handle up to 100 Watts of power and requires no external tuning.

This wideband, multi-function antenna developed by Cooper Antennas Ltd is particularly suited to tactical military communications. Rugged design ensures reliability in world wide conditions of service on helicopters and subsonic aircraft, operating to 40,000 ft and up to speeds of M0.8.

Use of a top loading element optimizes efficiency in VHF and the antenna provides omnidirectional radiation throughout the operating frequency range. The element is DC grounded for voltage transient protection. Unique element shaping preserves elevation pattern throughout frequency band.