The 'Youloop' is a passive receiving antenna, which is constructed according to the principle of the Möbius loop. Here, the inner and outer conductors of a coaxial cable are interchanged at one point, resulting in a long conductor in several turns. For long wavelengths, this construction is electrically symmetrical, which compensates for interference on the long bands and makes the antenna very low-noise. To maintain this electrical symmetry over a wider frequency range and to make it independent of the feed line, a balun is used at the feed point.

The Airspy Youloop is constructed from three very light semi-rigid cables with SMA connectors. The cable pieces can be rolled up to very small dimensions, so the antenna can be easily transported in the side pocket of a suitcase or similar. The antenna can be set up in a few seconds, it can be hung in the window with a suction cup or a string. The Youloop is not weatherproof, so if you want to use the antenna outdoors for a long time, you must seal the joints with self-welding tape.

The Youloop antenna can be used for a wide frequency range from long wave to medium wave and short wave. In principle, all types of receivers are suitable, but very low-noise receivers such as the Airspy HF+ Discovery are particularly suitable.