for example but not limited to the frequency range of approximately 160 khz 190 khz yielding a near field operating range of approximately 200 meters frequencies lower and higher than this can be used with an accompanying change in the near field range improving with lower frequencies and antenna efficiency for an antenna of a given size improving with higher frequencies any dipole antenna creates an electromagnetic field which depends upon the distance and direction to the receiver or wand 14 which can be described by an u201c antenna pattern u201d diagram such as shown in fig5 where the surface depicts the surface of equi amplitude field values since both a transmitting and a receiving dipole antenna are described by such a pattern a significant problem for the search and rescue application arises in operation for example firstly a searcher may begin near the minimum field region or u201c waist u201d of the transmitter 39 s field pattern and hence obtain no clue as to the presence or preferred search direction until they have left that location and or reoriented their receiving antenna secondly if polarization relationships are considered it can be shown that the searcher will be drawn into a pattern of movement by their attempts to maximize the received signal that has them walk a large arc around the source such that final approach is always towards one of the maximum field transmitting directions of the source finally because of the symmetry of the receiving antenna pattern there.