leaky feeder info
Leaky Feeder Radio Systems (using a radiating cable)
All Raveon data radios can be equipped with a radiating coaxial cable as an antenna for use as a leaky feeder system in areas such as, underground mines and railways, inside industrial buildings, and any other enclosed area where direct line of contact may be difficult to produce with a standard antenna. Leaky Feeder systems are the best way of communication in underground mines currently available.
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.