Leaky Feeder System
The Leaky Feeder System is a Radio Frequency Communication Solution to supply reliable but also vital communication between personnel above and underground and also for the communication for control and management systems in the mine.
The system utilize standard hand radios with standard repeaters.
Up to 16Channels of Radio Signals are propagated through the underground tunnels via the Head End Combiner that receives and transmits the radio signal using a special Leaky Feeder Cable that is fed through all main tunnels. This Radio signals are radiated for a distance of around 60meters around this Leaky Feeder Cable depending on the system used.
The system utilizes two sets of frequencies for communication. One set is named Uplink and the other DownLink.
Uplink would be the transmission from the Hand Radio used by personnel via the Leaky Feeder Cable, Head End Combiner and is then received by the Repeater. The Repeater then on it's turn transmits the DownLink via the Head End Combiner using the Leaky Feeder Cable to all Hand Radios within range of the cable.
The Radio Signal propagated via the Leaky Feeder Cable, continuously radiate providing reception by Hand Radios. Due to this radiation the losses on this cable need to be corrected to keep the signal strength at a acceptable level. This is done by inserting a Bi-Directional Mini In-Line Amplifier, usually every 350meters on the cable, that would bring the signal levels within acceptable levels for proper system performance.
The Bi-Directional Mini In-Line Amplifier uses a DC voltage present on the Leaky Feeder Cable. This DC Voltage is re-inserted on the cable after every few amplifiers by using a Bi-Directional Power Coupler to make sure the voltage on the cable is sufficient for the Amplifier to function properly.
| Leaky Feeder Repeater | Receiver of UpLink and Transmission of DownLink Radio Signals |
| Head End Combiner | Combine 16 Repeaters, at different frequencies, into a set of 4 Leaky Feeder Arterials, with Power Inserted, running into the Tunnel System |
| Bi-Directional Power Coupler | Insert Power on the Leaky Feeder Cable to provide another length of cable and Amplifiers with Power |
| Junction Box | Connection between Leaky Feeder Cables for Extensions and repairs on Damaged Cables |
| Splitter Box | 3 and 4 Way Splitters to Split the Leaky Feeder Cable for distribution through the Tunnel System |
| Mini Line Amplifier | Amplifies the Bi-directional Radio Signal Transported in the Leaky Feeder Cable |
| Hand Radio | Radios that is set to Leaky Feeder System Up- and DownLink frequencies |