Shielded underground cable detection by electromagnetic radiation

Electromagnetic radiation from a signal injected into a cable is analyzed with a view to locating underground power cable by detecting the radiation above ground. There exists an optimum frequency band for each cable type, despite the fact that the metal shield surrounding the cable suggests the use of as low a frequency as possible. Equipment consisting of a simple 50-kc mains-operated signal generator and a portable transistorized detector unit that can locate cable through ten feet of soil is described