Headend Equipment

The Headend includes the equipment necessary to operate the overall Leaky Feeder distribution system. The Headend provides for the following roles:

• Connection to the Leaky Feeder cable network.
• Connection to the surface antenna network.
• Modulation and Demodulation of the VHF signals.
• Splitting and combining of multiple channels.
  

  VDV Headend

• Powering the overall Leaky Feeder network.
• Diagnostics via an Amp/Voltmeter.
• Correct impedance matching.

The Headend equipment can also include additional items such as telephone interconnect units for interfacing to the mine PABX system. The Headend is usually contained within a suitable 19″ rack enclosure, this allows for easy maintenance

Multi-coupling used when greater than 3 Channels are to be Operated.

and servicing of the system. Typically for an average VDV system of 4 channels the Headend can be installed in one enclosure. For larger systems, that is when up to 16 channels are utilised, the Headend will usually be installed in two (2) enclosures.

The Headend comprises several components or modules, these include the following:

• Transmitter/Receiver Splitter Combiner
• 16 Channel Line Splitter Combiner
• Radio Repeaters
• Power Supply
• 19″ Rack Enclosure

Surface Communications

Surface Communications

Direct relay of the VHF signal to surface areas, or interface to a separate surface communication system (such as UHF), can be provided when required.