MX920 Base Station/Repeater

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Minimum performance to exceed the following for 135MHz to 520MHz*:

  • AS4295-1995,
  • R&TTE EC Directive 1995/05/EC
  • EN300 086 –1,2 (2001- 03),
  • EN 300 113, EN 301 489 – 1,5 (2002 – 08)
  • EN 60950 (2000)
  • RFS25, RFS26, RFS32,
  • TIA/EIA-603,
  • BAPT 225 ZV 1/2098 (German soft keying),
  • FCC Part 22, 74, 90, 90.210, 80.475,
  • MIL-STD-810E (Parts thereof),

* Conforms but not all bands approved.


Frequency Range: Coverage 148-520 MHz.

New!! The MX920 product is now capable of operating over extended frequency limits

Base Model Nom. Band SW. BW RX Frequency
EX-Limit Low
RX Frequency
EX-Limit Hi
TX Frequency
EX-Limit Low
TX Frequency
EX-Limit Hi
MX920D3 148-174 MHz 26 135 MHz 178 MHz 132 MHz 180 MHz
MX920L3 350-385 MHz 35 335 MHz 390 MHz 325 MHz 408 MHz
MX920N2 400-435 MHz 35 380 MHz 445 MHz 380 MHz 445 MHz
MX920O2 435-470 MHz 35 420 MHz 480 MHz 420 MHz 485 MHz
MX920P2 450-485 MHz 35 440 MHz 500 MHz 450 MHz 500 MHz
MX920Q 485-520 MHz 35 475 MHz 530 MHz 460 MHz 520 MHz

Note# When operating the MX920 in the extended frequency limits, the switching bandwidth (SW.BW) still applies. Depending on the user frequencies, some re-alignment may be necessary when working in the extend frequency range.

Synthesis Method Non-mixing PLL.
Fractional N synthesizer.
Modulation Direct FM two-point method.
Channel Spacing Programmable 25kHz / 12.5 kHz
Synthesizer Step Size 6.25kHz or 5kHz auto select
Channels 99 front panel selectable,
255 PC software selectable
Supply Voltage 13.8 +/- 20% or optional AC mains input
DC Power Consumption <250 mA receive, typ 230mA
<10A for 50W TX RF, typ 7.8A
Operating Temperature -30 to +60C
Physical Size 120mm Height x 355mm Width
Standard LED indicators Power, RX, TX, Tone, Alert, Repeater
Standard Switches Repeater ON/OFF, Accessory ON/OFF
Standard Controls Volume, Squelch
Interface Front panel Microphone accessory socket.
Weight 8kg to 15kg depending on options




Transmitter Feature
RF Power Output 1W to 50W
Frequency Stability >300MHz
< 300MHz
–10 to 60C for 1.5PPM, –30 to -10C for 2.5PPM
–10 to 60C for 2.5PPM, –30 to -10C for 5PPM
Audio Response Flat within +1,-3dB across BW
Audio Bandwidth 300Hz to 3000Hz
Modulation Distortion Less than 3% @ 60% deviation
S/N Ratio Better than 46dB (WB).
Better than 42dB (NB).
Spurii Better than -90dBc
RF Switching Bandwidth Full Sub band
RF Switching Bandwidth PA Full Sub band
Duty Cycle 100% for 50W RF output
RF Rise Time <10mS with continuous VCO selected
<200mS with VCO in cold standby




Receiver Feature
Sensitivity Better than -117dBm for 12dB SINAD, typ –120dBm
Selectivity 135-520MHz More than 85dB for 25kHz adj channel.
more than 75dB for 12.5kHz adj channel
Audio Bandwidth 300Hz to 3000Hz (+1,-3dB)
Image Freq Rejection Better than 100dB
Spurious Response Immunity Better than 80dB
Intermodulation Immunity Better than 80dB
Blocking Better than 100dB at +/- 1MHz point
Distortion Less than 3% @ 60% deviation
Frequency Stability 1.5PPM for –10 to 60C,
2.5PPM for –30 to -10C
S/N Ratio Better than 46dB (WB)
Better than 40dB (NB)
Co-Channel Rejection Better than 5dB
RF Switching Bandwidth Equal to Sub band allocation
Receiver Front End BW Equal to Sub band allocation
Receiver Audio Power 3 Watts nominal, 5 Watts peak



  • Full Duplex Base Station or Repeater selectable from front panel
  • Fully Programmable / Configurable via PC or serial device.
  • System independent, no additional software program required.
  • High Speed CTCSS, Full Duplex DCS/DPL
  • Remote controllable Multi tone CTCSS community decoder
  • 100% full power duty cycle
  • Multi staged TX VF processing with triple limiters
  • Flash Firmware Upgrade Capable
  • Battery backup system ready
  • Built In Test Equipment (B.I.T.E.) and remote diagnostics
  • Broad Band High Efficiency LDMOS PA module
  • RX & TX Switching BW covers full sub band
  • Fast Serial Data Interface
  • Full Digital alignment and calibration
  • Low RFI and EMI emission design
  • Controlled TX RF envelope
  • Low current consumption
  • DTMF encoder and decoder
  • Latest technology, full SMD
  • Advanced and optimized RF design
  • High performance 16 bit Flash processor
  • Programmable 12.5/25kHz channel spacing
  • Configurable Function Front Panel LEDs
  • Ultra bright LEDs viewable in Sunlight with digital intensity control
  • Simple and fast disassembly for service
  • Precision internal shielding system
  • Minimal technician adjustments for future maintenance
  • Design spec –40 to 70 degrees C
  • Low aging oscillators
  • Universal microphone input circuit
  • Minimal interconnections
  • Options cans be easily retrofitted
  • Minimal mechanical adjustments
  • Front end RX filter never needs realignment
  • Built in TX modulation alignment circuit
  • Built in auto alignment software guides technician
  • Fast and simple disassembly
  • Built on proven technology
  • Configuration password protected
  • Virtual elimination of internal wiring
  • Field swappable modules include auto alignment
  • Elimination of helical filters, quadrature coils, MCF matching and trim potentiometers


  • Desk Mic
  • Internal PSU
  • Internal Duplexer
  • Internal Simplex relay
  • Internal Battery backup
  • Horizontal or vertical desktop case
  • Rackmount tray
  • Wall mountable kit
  • Virtual PC Console including ANI / CTCSS / DCS / 5TONE / DTMF display (future proposed)



  • Not all items and features initially available.
  • Future software releases and features can be Flash Memory upgraded.
  • Due to ongoing development we reserve the right to alter specifications without notice.

Reliable Radio Communications. When You Need It Most.                        2013 Spectra Engineering Pty Ltd