SPECTRA ENGINEERING PTY LTD DMR Repeater Technical Manual MX940
Technical Manual MX940 Base Station & Repeater Spectra Engineering Pty Ltd ABN 65 057 696 438 731 Marshall Road Malaga Western Australia 6090 Tel: +61-8-92482755 Fax: +61-8-92482756 Email: info@spectraeng.com.au Web: www.spectraeng.com.au In order to continually improve our products, Spectra Engineering Pty Ltd reserves the right to alter, without notice and at any time, the equipment and specifications described in this document.
MX940 Base Station & Repeater Technical Manual Regulatory Information FCC COMPLIANCE This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation. FCC Interference Warning Note: This equipment generates, uses and can radiate radio frequency energy.
Technical Manual MX940 Base Station & Repeater Record Of Changes Any changes to this manual are recorded on this list. Spectra Engineering may issue replacement pages to you from time to time. If any updates are issued, you will also receive a replacement for this page. Date Version Chapter Changes Pages Changed June 2022 1.0.0 All - Initial Release All © SPECTRA ENGINEERING 2022 Revision 1.0.
MX940 Base Station & Repeater Technical Manual SAFETY SUMMARY Only the MX940 self contained power supply, if installed, contains dangerous mains voltages within. Normal operation and use of the MX940 does not expose the operator or service technician to high voltage parts. The power supply is isolated from and maybe removed safely from the main chassis. For servicing, please return to your nearest distributor. No fuses or user-serviceable parts are within the power supply module.
Technical Manual Table of Contents Table of Contents 1. General Description ........................................................................................... 1 1.1 Physical Description .................................................................................. 2 1.1.1 Front Panel .................................................................................. 3 1.2 Module Functional Description ................................................................. 6 1.2.
MX940 Base Station & Repeater vi Technical Manual © SPECTRA ENGINEERING 2022 Revision 1.0.
Technical Manual Table of Contents List of Tables Table 1-1 LED Functions ................................................................................................ 4 Table 1-2 Rear Panel Connections .................................................................................. 5 Table 2-1 Micro Controller Jumper .............................................................................. 10 Table 4-1 Peak Deviation Settings .....................................................................
MX940 Base Station & Repeater Technical Manual List of Figures Figure 1-1 MX940 Front Horizontal View ....................................................................... 3 Figure 1-2 MX940 Rear Panel. ....................................................................................... 5 Figure 4-1 Mod Under (increase level) ......................................................................... 16 Figure 4-2 Mod Over (decrease level) ...............................................................
Technical Manual 1. General Description The MX940 series employs state of the art design and construction methods to deliver a range of high performance, very reliable radio base stations and repeaters. They are ideally suited for use in VHF or UHF two-way voice communications radio systems.
MX940 Base Station & Repeater Technical Manual In addition, the MX940 can be fitted with options, not being limited to the following: Power supply Duplexer Batteries for power backup system. Note: Not all options and features may be available at the time of order. Please also refer to Spectra Engineering’s web site for software feature upgrades and additional documentation as available. www.spectraeng.com.au 1.
Technical Manual Installation and Operation 1.1.1 Front Panel 1.1.1.1 Standard Front Panel The MX940 front panel provides the user with real time status of the MX940. Figure 1-1 MX940 Front Horizontal View Mute / Squelch Adjustment The squelch is used to eliminate any annoying background noise when there are no signals present. This is pre-calibrated at the factory, to provide the user with 5 useable settings. These can be set via the channel edit menu.
MX940 Base Station & Repeater Technical Manual Table 1-1 below explains the functions of the front panel LED's. Each LED indicates the status of the MX940 in real time. LED COLOR FUNCTION POWER AQUA Indicates the power supply voltage is within limits. No display indicates the voltage is not normal. ANALOG BLUE Current Channel programmed for FM mode. RX A AQUA Analog Mode: A signal is being received by the receiver or the receivers squelch is open.
Technical Manual 1.1.1.2 Installation and Operation Rear Panel Conn Type Function Description Mini-Fit Jr ,4P DC Power input 13.8 Volt DC power input. N TYPE N type RX input The input to the receiver for full duplex operation. N TYPE TX output The RF power output from the transmitter for full duplex operation. RJ45 Ethernet Gives the base station an identity as a network element, and provides the physical connections for the Ethernet USB USB TYPE B Serial Data interface.
MX940 Base Station & Repeater Technical Manual 1.2 Module Functional Description 1.2.1 RF Module and Main Controller Assembly The MX940 consists of a full duplex RF module with its own shielded metal housing and a Main Controller board integrated on a single PCB. Using advanced yet simplified circuit designs, the size and complexity is reduced.
Technical Manual Installation and Operation transmit and received audio is passed to and from the Exciter and Receiver sections as well as providing all other audio signalling functions of the transceiver. An on onboard EEPROM stores all of the user channel related data such as frequencies, CTCSS tones etc.
MX940 Base Station & Repeater Technical Manual 2. Installation and Operation 2.1 Installation The MX940 Radio is securely packed for transport within a pasteboard container. Before unpacking the MX940 radio, please inspect the packaging for signs of damage and report any damage to your MX940 distributor. Upon unpacking of the MX940 radio, please ensure that all items shipped were received, report any missing items to your MX940 distributor.
Technical Manual Installation and Operation 2.2 Screw Head Types Modern screws employ a wide variety of drive designs, each requiring a different kind of tools to drive in or extract them. Spectra Engineering has chosen the Pozidriv ® screw head and screwdriver as it preferred screw type on all of its products, sizes 1 & 2. This is because the Pozidriv system is the choice for high volume assembly operations. It provides self-centring system and excellent driving control with less operator fatigue.
MX940 Base Station & Repeater Technical Manual 2.3 Operation The MX940 can operate in local control Base Station mode or Repeater mode via the front panel controls. Setting up the MX940 to operate in the wanted settings is straightforward and involves one main step. Using a PC or handheld serial computer running standard communications terminal software, connect the PC USB port to the radio USB -type B socket at the rear panel of the MX940. Set the appropriate parameters as required.
Technical Manual 2.3.1.4 Installation and Operation Configure Alarm LED The MX940 has an LED to display the status of alarms. The alarm trigger conditions can be set using the built-in radio configuration menu system software. The LED can be set to trigger on low forward power, high reflected power, power supply voltage out of range, VCOs unlocked and high PA temperature. The status of the alarm conditions can be expanded in the on-line diagnostics mode.
MX940 Base Station & Repeater Technical Manual 3. Options The MX940 also has the provision to mount a Duplexer internally using the a optional mounting plate. Wiring for this cases must be performed by the appropriate qualified personal. Please contact your Dealer or Distributor should you require the appropriate assistance. 12 © SPECTRA ENGINEERING 2022 Revision 1.0.
Technical Manual Installation and Operation 4. Alignment and Testing The MX940 test and alignment section assumes that the radio is a working module. Due to ongoing development the instructions may vary please refer to www.spectraeng.com.au for updates. 4.1 Transceiver Setup, Calibration and Alignment This section explains how to setup, calibrate and align the complete MX940 Base Station. A number of procedures are required to fully initialise the MX940.
MX940 Base Station & Repeater Technical Manual The channel may be edited via the Channel Edit Screen of the built menu system software. The current operational channel can be selected by using the software channel select command. The MX940 comes from the factory pre-aligned, so in most cases adjustment will not be required. The MX940 employs Frequency Alignment Compensation, which is setup during factory alignment.. This reduce the need of individual channel alignment for Tx Power and modulation depth.
Technical Manual Installation and Operation 4.1.7 Temperature Calibration The temperature calibration is used to calibrate the temperature meter on the in-built menu system via Diagnostics Screen and the temperature controlled switch/alarm points. The procedure requires dummy cable for SKB on the micro controller having a 2060-ohm resistor between pins 4 and 6 of this connector of the MX940 Base Station. Temperature calibration is done via the software command.
MX940 Base Station & Repeater Technical Manual 7. Adjust the Reference Deviation digital potentiometer until the top of the waveform is flat. If the waveform top droops increase the level (see Figure 4-1) and if it peaks reduce the level (see Figure 4-2). 8. Repeat steps 5 through to 9 until the correct peak deviation and modulation balance is obtained.
Technical Manual Installation and Operation 4.1.11 Nominal Deviation The required nominal deviation is dependent on whether the radio is programmed for either narrow or wide. The following table lists the required level for each case: Bandwidth FM Nominal Deviation (kHz) Narrow (12.5kHz spacing) 1.5 Wide (25kHz spacing) 3.0 Table 4-2 Nominal Deviation . 4.1.12 Mute Threshold Setting Test Equipment: PC with Terminal software RF Communications test set +13.
MX940 Base Station & Repeater Technical Manual 5. Appendices 5.1 MX940 Interface Connections The user connections to the MX940 are all made via the Front and rear panel where the following connectors are located. Conn Type Function Description Mini-Fit Jr ,4P DC Power input 13.8 Volt DC power input. N TYPE N type RX input The input to the receiver for full duplex operation. N TYPE TX output The RF power output from the transmitter for full duplex operation.
Technical Manual Installation and Operation 5.2.2 CN4 Pinouts Figure 4.1 CN4 DC INPUT Supply (Mini-Fit Jr Connector) PINS Description 1 GND 2 GND 3 + 13V8 DC 4 + 13V8 DC © SPECTRA ENGINEERING 2022 Revision 1.0.
MX940 Base Station & Repeater Technical Manual 5.3 MX940 Specifications Minimum performance to exceed the following for 30 MHz to 960 MHz*: AS4295 ETS 300 086, ETS 300 113, ETS 300 489 FCC Part 90 TIA/EIA-603 CE Marking IC (ISED) *Conforms but may not be approved. Consult Spectra Engineering regarding current type approvals and for latest and current MX940 Specification Data sheet. 5.3.
Technical Manual Installation and Operation 5.3.2 General Parameter Specification MX940 Rack Size: 2RU Case MX940 Overall Physical Size 89mm high, 330mm deep, 483mm wide * Requires extra depth (40mm) for Fan operation. Weight <6 kg Supply Voltage: 13.8V +/- 20%. Power Consumption: <500mA receive, typical 480mA. (TX VCO off). <10A for 50W TX RF @13.8VDC. Operating Temperature: -30 to +60 C. Individual Module Dimensions: Main board W=153, L=221mm, H = 22mm. PA W=78, L=300, H = 60mm.
MX940 Base Station & Repeater Technical Manual 5.3.3 Transmit Measured in accordance with TIA/EIA-603 standards. Parameter Specification RF Power Output: 1W to 50W or 100W (See model type) Frequency Stability: > 300 MHz < 300 MHz 1.0 PPM for –30 to 60C, 2.5PPM for –30 to 60C, Audio response: Flat within +1, -3 dB across bandwidth Audio Bandwidth VF input: 300 Hz to 3000 Hz LPF Modulation Distortion: Less than 3% at 60% deviation. S/N Ratio: Better than 50 dB, wide band.
Technical Manual Installation and Operation 5.3.4 Receive Measured in accordance with TIA/EIA-603 standards. Parameter Specification Sensitivity: Better than –117 dBm for 12 dB SINAD. Typical –121 dBm. Selectivity 135-520MHz: More than 82 dB for 25 kHz adj channel. Typical 85dB More than 75 dB for 12.5 kHz adj channel. Spurious Resp: Better than 80 dB. Intermodulation: 82-88 dB. Blocking: Better than 100 dB at +/- 1 MHz point. Co-Channel Rejection: Better than 5 dB.
MX940 Base Station & Repeater Technical Manual 5.4 MX940 Model Number Configuration Guide The MX940 build can be specified by the model number. The diagram below shows how the model number is derived from the wanted options. Consult Spectra for availability details on specific configurations and options. Tx Power H 50 Watt V 100 Watts MX940 Freq Band Band Frequency D5° N5 P5° 148-174 MHz 400-470 MHz 450-520 MHz Table 5-6 MX940 frequencies bands Due to ongoing development please refer to www.
