Teaching aid for UHF radio navigation - has base divided in two by line of positions and aircraft mark movable against spring and magnet tension

摘要

The radio navigation leaching aid and a round base divided by a line of position in left-hand and right-hand halves, with the latter completely covered with a ferromagnetic metal. The base is further divided in four quadrants by a second line perpendicular to the above. An aircraft mark can be placed by hand in any position. It has a pointer movable in a plane parallel to the base on a fixed scale. When the aircraft mark is on the non-ferromagnetic half of the base, the pointer is pressed to one end position by a spring, and on the ferromagnetic half it is moved by a magnet to the other end position.