SMX920 Base Station & Repeater
Technical Manual
RELM/
BK RADIO
2
♦
Built in diagnostics
♦
Built in community multi-tone style repeater
♦
CTCSS, Full duplex DCS, 5 tone, local speaker and many other options included
as standard
♦
Programmable channel spacing
♦
Low receiver standby current consumption
♦
Flash upgradeable
In addition, the SMX920 can be fitted with options, not being limited to the following:
♦
Simplex antenna changeover relay
♦
Power supply
♦
Duplexer
♦
Batteries for power backup system
♦
Horizontal or vertical standing
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Rack mount
♦
Wall mount kit
♦
Desk microphone
For further information see Section 4, additionally, please contact RELM Wireless
Corporation.
Note: Not all options and features may be available at the time of order. Please also
refer to RELM’s web site for software feature upgrades and additional documentation
as available.
www.RELM.com
1.1 Physical
Description
The SMX920 is a compact fully self contained Base Station and Repeater. It is
designed to stand either horizontally or vertically on a desk or like. An optional 19"
3RU rack kit allows the standard horizontal version to sit on rack-mounted tray. The
depth of the unit is 330 mm and the weight is less than 9 kg without the power supply,
duplexer or battery fitted. With the addition of the Wall mount kit, the vertical
SMX920 can be mounted against a wall for convenience.
The unit consists of two main sub assemblies, the main RF assembly and a Power
Amplifier Module. These modules are housed in sturdy steel case.
An internal power supply may also be pre-installed or retrofitted at a later date. As it
is a fully self contained Power Supply, it may also be safely operated outside the
SMX920 without any exposed mains voltage terminals.
The SMX920 features a high degree of RFI and EMI screening throughout the design
and construction. The receiver and exciter RF circuits are contained in solid
aluminium enclosure. The PA module is contained in a special compact and efficient
extrusion for minimum harmonic radiation. This design results in low conducted and
radiated emissions and minimal susceptibility to RFI and EMI.
User interface is via the front panel microphone socket which includes a serial port for
software programming and upgrading.
