La description

Key Facts Stationary and semi-mobile UHF DF antenna The R&S®ADD071 covers the 1.3 GHz to 3 GHz frequency range and is suitable for stationary as well as semimobile applications, preferably mounted on a mast. An R&S®ADD197 or R&S®ADD196 antenna can be mounted above the R&S®ADD071 due to its robust design. This type of DF antenna system then covers the entire 20 MHz to 3 GHz frequency range. The lower left picture shows how the R&S®ADD071 and R&S®ADD196 can be combined to create a DF antenna system for semi-mobile applications.
''