 Additionally, the sets demonstrated a serious problem with ground reflections. The broadcast antenna sent out the pulse over a very wide area covering the entire forward side of the aircraft. This meant that some of the broadcast energy struck the ground and reflected back to the receiver. The result was a solid line across the display at a distance equal to the aircraft's altitude, beyond which nothing could be seen. This was fine when the aircraft was flying at 15,000 feet (4.6 km) or more and the ground return was at about the maximum useful range, but meant that interceptions at lower altitudes offered increasingly shorter range.
