Soil searching

Low-power radio is primarily associated with remote control, telemetry and short-range communications. It also plays a vital role in the location and maintenance of underground pipes and cables. The various ways in which radio emissions can be used to detect pipes and cables are illustrated by the three operating modes of the CAT (cable avoidance tool), the base product for pipe and cable detection manufactured. by Radiodetection Ltd. In the 'power' mode, the CAT detects signals derived from the mains supply network; in 'Radio' mode, it detects reradiated low-frequency broadcast signals, and, in 'Genny' mode, it detects deliberately imposed signals. The operating frequencies and location depths corresponding to these three modes are indicated. The CAT is a battery-powered, hand-held product with a loudspeaker providing a sound signal to indicate the amplitude of the received radiation.