The practical and very wideband R&S®HE300 active directional antenna locates transmitters and interference sources when combined with portable receivers (e.g. R&S®PR100). The three exchangeable antenna modules supplied with the antenna cover the 20 MHz to 7.5 GHz frequency range. An additional module (R&S®HE300HF for 9 kHz to 20 MHz) is available as an option. The modules can be plugged into the handle with the correct orientation for vertical or horizontal polarization and then mechanically locked in place.