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1.7 Connecting the Central Receiver in a Typical Roof Top
Installation
The following section describes how a Central Receiver should be
connected when used in a typical permanent roof top installation.
Location of the Central Receiver
The domo Central Receiver has been designed so that the
downconverter units are mounted remotely from the receiver unit, and
connected via the 3-5 metre TNC cable.
Note: If a longer cable run is required between the Central Receiver and the Down
Converter, the DCX High Gain down converter should be specified. The DCX will typically
drive 25-50m of cable.
The domo SOLO4 Central Receiver is a standard 19’’ rack unit
equipment and is designed to be mounted in an equipment rack or
shelter and must not be exposed to the elements. The receiver is
neither splash resistant, nor waterproof, so it should not be exposed to
moisture. The domo SOLO4 Central receiver is not self cooling and is
fitted with equipment fans. It is essential that sufficient free air space is
available on both sides of the Central Receiver to allow and unrestricted
flow of air through the equipment. Failure to do so may damage the
Central Receiver.
In a typical installation the Central Receiver will be installed on the roof
of a tall building, in this situation, the Central Receiver will either be in a
weatherproof box (domo can supply on request) mounted to the parapet
wall of the building, or will be installed in an equipment rack typically in
the lift house of the building.
Diversity, Antenna Positioning and Use of Down Converters
Note: Domo down converters can be damaged by static electricity discharge when
connecting antennas. It is suggested that only antennas with built in DC path to ground
are employed to avoid static damage. If this can not be achieved then antennas should be
shorted to ground before connection to the down converter.
The domo SOLO4 Central Receiver is a quad diversity receiver and will
give optimum results only when all four antennas are deployed. The
downconverter boxes should be connected to the receiver, by
connecting the 3m TNC cables supplied between the down converter
connector labelled ‘RX / IF OUT’ and the receiver connector labelled
‘ANT A / B / C / D’. Care should be taken not to over tighten the TNC
connectors. Where longer cable runs are required the DCX high gain
down converter should be employed.
The downconverters convert the RF signal down from microwave
frequencies to the UHF band, which allows the signals to be run along
longer cables without degradation. In the case of the domo SOLO
Central Receiver 3 metre long cables are provided, allowing the
downconverters to be positioned remotely from the receiver.
