Mine Radio Underground Communications Leaky Feeder Radio System
A leaky feeder system is used for underground mining or tunnel environments where line-of-sight radio communication is difficult or impossible to achieve. Radios are connected with a coaxial cable with a receiver (Rx) port on one end and a transmitter port (Tx) on the other side of the radio.
Leaky Feeder systems work by using a specially made coaxial cable, radiating cable, as an antenna, which is designed specifically with slots cut into the outer shielding to let the radio waves it would normally carry to a standard antenna, in and out along the length of the cable. Doing this turns the entire cable into one long antenna emitting and receiving along the entire length. This process makes the signal weaker over the distance of the cable and eventually gets to a point where the radio waves transmitted are to weak to be of use. Because of this problem, the use of line amplifiers is required at points between 350-500 meters, to boost the signal back up to a receivable level by your other points of contact.