"This report adds to the current body of underground communication system design knowledge by: 1. accurately defining (measuring) the 12 dB SINAD sensitivity of the system receivers and then starting the equivalent magnetic field strength (Hs) in uA/m; 2. showing that when a passageway repeater is used in loop to loop via the line communication link that the received signal level dependence on line current is only at the first power of distance; and, 3. maximizing the transmit moment is extremely important in the design of the transmit antenna network." - NIOSHTIC-2 NIOSHTIC no. 20031946

National Institute for Occupational Safety and Health