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RFM2000
Intrinsically Safe Underground Radio (Leaky Feeder) System
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The RFM2000 intrinsically safe underground radio (leaky feeder) system
is designed to enable VHF radio frequencies to be transmitted and
received in underground roadways and tunnels up to 25 Km in length.
The age old problem of strata absorption has been overcome by using
a radiating cable (leaky feeder) interspaced with 2 way repeater amplifiers
at 350 to 500 metre intervals.
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 CENELEC Certified
VHF High Band
Mulit Channel
25KM of cover
Telephone interconnect
Speech, signalling
and data
Intrinsically safe
Radiating cable
(leaky feeder)
25 years experience
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The
RFM system comprises a base station, radiating cable, in line repeater
amplifiers, passive splitters and mobile radio
transceivers.
Various
interconnect facilities are offered to enable integration to other radio
systems and other types of communications systems.
The RFM
system has taken the opportunity of using standard off the shelf pocket
phones for intrinsically safe and non intrinsically
safe applications. A rugged, robust loudspeaking
transceiver is offered for mounting onto mobile vehicles such as locomotives,
monorails, free steered vehicles and rope driven haulage's.
The repeaters
are powered from the base station and additional power is only needed
for complex long distance systems.
Interface
circuitry is offered to allow radio telephones to be used and connection
to other types of communication systems for
loudspeaking P.A.
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Base
unit
A
variety of base stations are offered to suit individual customer applications.
The
base station houses the necessary transmitters, receivers and
other interface circuitry.
Power for the repeater amplifiers is supplied from the base station
via the radiating cable.
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Radiating Cable (Leaky Feeder)
The cable
is of a coaxial construction specially designed to allow signals to
radiate and allow signals to be accepted from
portable radios anywhere along its length.
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Repeaters
The
repeater circuitry is the heart of the system and it's design ensures
the signal strength to be consistent throughout
the whole network.
The repeater
acts as a two way amplifier simultaneously capable of handling multiple
channels.
The repeaters
would normally be spaced at 350 to 500 metre intervals.
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Passive Splitter
Because most underground complexes have many tunnels, it is necessary
to be able to split the system at roadway junctions.
The passive splitter
allows this to happen without significant loss of signal strength.
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Termination Unit
To
maintain a balanced system each end of the radiating cable requires
to be terminated.
The termination
unit ensures this balancing will take place.
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Radio Pocket Phone
A
variety of radio pocket phones and radio telephones are available for
personnel use, depending upon customer requirements.
These are
standard units usually available in most countries.
Frequency selection
and mode of operation requires to be stated when buying independently,
or units can be specified and supplied by GAI-Tronics.
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Vehicle Radios
Because
of the special nature of this application GAI-Tronics have a purpose
made unit available with a loudspeaker stage and handset
to overcome ambient noise levels.
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