Table of Contents
Advertisement
Quick Links
Advertisement
Table of Contents
Related Manuals for RELM BK RADIO SDMX920
Summary of Contents for RELM BK RADIO SDMX920
- Page 1 Base Station and Repeater SMX920 SDMX920 VER. 1.1.4 0300-30973-700_REV 07-14...
- Page 3 Technical Manual MX920 Base Station & Repeater RELM Wireless Corporation 7100 Technology Drive West Melbourne, FL 32904 Front Desk: (321) 984-1414 Sales: (800) 821-2900 Service: (800) 422-6281 www.RELM.com 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.
- Page 4 MX920 Base Station & Repeater Technical Manual This page left blank intentionally © SPECTRA ENGINEERING 2003 Revision 1.1.4...
- Page 5 Technical Manual MX920 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.
- Page 6 MX920 Base Station & Repeater Technical Manual SAFETY SUMMARY Only the MX920’s self contained power supply, if installed, contains dangerous mains voltages within. Normal operation and use of the MX920 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.
-
Page 7: Table Of Contents
Technical Manual Table of Contents Table of Contents General Description................... 1 Physical Description.................. 2 1.1.1 Front Panel .................. 3 Module Functional Description ..............6 1.2.1 RF Module and Main Controller Assembly ......... 6 1.2.2 Power Amplifier Module .............. 7 Installation and Operation................8 Installation .................... - Page 8 MX920 Base Station & Repeater Technical Manual Receiver Section..................23 6.3.1 6.3.2 RX Front End 6.3.3 IF Section Excit r 6.4.1 6.4.2 Powe r Alignment and Testing ..................27 Transceiver Setup, Calibration and Alignment ........27 7.1.1 Setting the Model Number and Serial Number......27 7.1.2 Setting the Configuration Information ........
- Page 9 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 5-1 Microprocessor Port Parameters..............17 Table 7-1 Peak Deviation Settings ................29 Table 7-2 Nominal Deviation ..................
- Page 10 MX920 Base Station & Repeater Technical Manual List of Figures Figure 1-1 MX920 Horizontal andVvertical types of Front Panel LEDs......3 Figure 1-2 MX920 Rear Panel with Power Supply and Duplexer fitted......5 Figure 7-1 Under (increase level) ................. 30 Figure 7-2 Over (decrease level)...................
-
Page 11: General Description
Technical Manual 1. General Description The MX920 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. Fractional synthesizers’... -
Page 12: Physical Description
MX920 Base Station & Repeater Technical Manual ♦ 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 ♦... -
Page 13: Front Panel
Technical Manual Installation and Operation 1.1.1 Front Panel 1.1.1.1 Standard Front Panel The MX920 front panel comes in both horizontal and vertical types, this can be see in the illustrated below. The front panel provides the user with real time status of the MX920. -
Page 14: Table 1-1 Led Functions
MX920 Base Station & Repeater Technical Manual When CTCSS is enabled the channel remains quiet until someone transmits using the same tone. Should the receiver be setup for the reception of a signalling tone, the 'Green RX LED' lamp with be on, also if it contains the correct tone the 'Yellow Tone LED' lamp will be lit, and audio out of the speaker will then be heard. -
Page 15: Table 1-2 Rear Panel Connections
Technical Manual Installation and Operation 1.1.1.2 Rear Panel The rear panel image shown has the internal Power supply fitted, alternatively the MX920 can be ordered without the Power Supply or it can be retrofitted at a later date should this be required. In the case of power being fed externally, the flying lead is then routed out through the cable clamp grommet supplied with all units. -
Page 16: Module Functional Description
MX920 Base Station & Repeater Technical Manual 1.2 Module Functional Description 1.2.1 RF Module and Main Controller Assembly The MX920 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. -
Page 17: Power Amplifier Module
Technical Manual Installation and Operation An on onboard EEPROM stores all of the user channel related data such as frequencies, CTCSS tones etc. A serial port at the Microphone accessory socket of the MX920 provides access to the Controller card software configurations for the purpose of the user to create and change this channel related information. -
Page 18: Installation And Operation
MX920 Base Station & Repeater Technical Manual 2. Installation and Operation 2.1 Installation MX920 series radios are securely packed for transport with special packers within a cardboard container. Before unpacking the MX920 radio, please inspect the packaging for signs of damage and report any damage to your MX920 distributor. Upon unpacking of the MX920 radio, please ensure that all items shipped were received, report any missing items to your MX920 distributor. -
Page 19: Operation
Technical Manual Installation and Operation Parallel sides Tapered sides Figure 1-2 Side View of screw Heads Exrta contact ridges Don’t used this type Used on All on Spectra products Spectra products Phillips Pozidriv Tapered driving flute Parrallel driving flute Figure 1-3 Screw driver Tip View 2.3 Operation The MX920 can operate in local control Base Station mode or Repeater mode via the front panel controls. -
Page 20: Table 2-1 Micro Controller Jumper
MX920 Base Station & Repeater Technical Manual 2.3.1.1 Micro Controller Jumper There is only one jumper and it is used for selecting the microcontroller operation mode. The user will not normally have to change the position of this jumper as it is only used in the initial factory setup. -
Page 21: Adjustments
Technical Manual Installation and Operation 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. Additionally, the ALERT LED may be configured to display the result of a valid tone signalling decode operation or another function subject to the software configuration within the MX920 firmware. -
Page 22: Standard Features
MX920 Base Station & Repeater Technical Manual 3. Standard Features 3.1 Programmable Channel Spacing The MX920 receiver can be programmed for either 12.5 kHz (Narrow Band) or 25 kHz (Wide Band) channel bandwidth. Switchable IF filters in the receiver and automatic 12.5 kHz / 25 kHz gain compensation in the audio paths make the change in bandwidth transparent to the user. - Page 23 Technical Manual Installation and Operation ♦ Channel Change Control Twin push wheel switches are fitted to the front panel to allow selection of the operating channel. When fitted this switch is wired to the channel select pins on SKC. 99/100 channels are selectable. Refer to Section 2.3.1.3 for more details on alternative channel select methods.
-
Page 24: Options
MX920 Base Station & Repeater Technical Manual 4. Options Due to ongoing development please refer to www.spectraeng.com.au for the latest revision of options . 4.1 Simplex Changeover Relay 4.1.1 Description For simplex applications an internally mounted coaxial changeover relay can be provided. - Page 25 Technical Manual Installation and Operation 2. Software switch ‘Simplex mode’ in the radio configuration menu system is switched ‘X’ as per Section 4.1 of the MX920 Manual. MX920 Testing: 1. Connect a Communications Test Set to the MX920. 2. Monitor the Low Level muted RX VF Audio (Pin1 of RJ45). 3.
-
Page 26: Technical Description
MX920 Base Station & Repeater Technical Manual 5. Technical Description The internal design of the MX920 is of a modular nature allowing for simple configuration and maintenance while ensuring minimal downtime. 5.1 Exciter Section RF from the VCO is at a nominal level of +3 dBm is applied to the fractional-N synthesiser main divider input. -
Page 27: General Radio Management
Technical Manual Installation and Operation and VF processing. The Received Signal Strength Indication (RSSI) is buffered and connected to the Micro Controller. RF from the VCO at a nominal level of +3 dBm is applied to the fractional-N synthesiser’s main divider input. This signal is compared with the reference oscillator frequency and the correction voltage from the synthesiser’s charge pump output is filtered then amplified by the non inverting low noise op amp. -
Page 28: Tx Signal Processing
MX920 Base Station & Repeater Technical Manual The FX828 (IC29) is a flexible predictive or non-predictive, full duplex CTCSS / Selcall encoder / decoder, DCS decoder, which is under the control of the microprocessor. 5.2.2 TX Signal Processing TX audio may be sourced from a number of different paths. These include Talk through audio, microphone and tone generators (ie Selcall, DTMF, DCS, CTCSS under micro controller control. -
Page 29: Rf Power Control
Technical Manual Installation and Operation 5.2.4 RF Power Control Forward power is controlled by the microprocessor through two mechanisms. Based on pre-programmed per channel adjustments the microprocessor sets the digital to analog converter output to a reference setting. IC28B serves as a comparator and, with the non-inverting input connected to the output of the digital to analog converter, is set up with a reference voltage. - Page 30 MX920 Base Station & Repeater Technical Manual A dual directional coupler consists of coupled microstrip transmission lines fabricated on the PCB artwork. The sampled RF energy is rectified to provide a proportional DC voltage output. The PTT signal enables the amplifier circuit by providing bias to the transistors. A thermistor TS I, physically located on the PA heatsink monitors the heatsink's temperature and is monitored by the Micro Controller.
-
Page 31: Mx920 Base Station Fault Finding Procedure
Technical Manual Installation and Operation 6. MX920 Base Station Fault Finding Procedure The following test equipment may be required for the following tests: ♦ MX920 in built Base Station Programming Utility ♦ RF Test Set (eg HP 8920 or equivalent) ♦... -
Page 32: Receiver Section
MX920 Base Station & Repeater Technical Manual ♦ If the Diagnostics shows abnormal, then check the voltage on pin 95 of IC1 on the Control Board. If the voltage is low ie <200mV then the likely fault is IC1. If the voltage is >200mV then the likely fault is within the PA module. ♦... -
Page 33: Microcontroller Section Of Pcb
Technical Manual Installation and Operation 6.2 Microcontroller Section of PCB Check fuse. If blown, replace with a 5x20 mm 3A fast blow fuse. Check jumper is in the correct position for operation. 6.3 Receiver Section 6.3.1 VCO Locking ♦ Using the in-built menu, check all Hardware settings are correct. ♦... -
Page 34: Excit R E
MX920 Base Station & Repeater Technical Manual ♦ If the RX centre frequency cannot be adjusted the TCXO may be faulty. ♦ Distortion should be less than 3%. ♦ If the distortion is high then FL3A, FL3B or FL4 may be faulty. ♦... - Page 35 Technical Manual Installation and Operation Remove link from TR2. Measure current consumption, adjust RV1 so that current is 2Amp total (VHF & UHF). Measure gate volts ≈ 3.9V ♦ Connect the RF output Connector CN3 with a coax lead to a power meter. Turn ON the supply voltage and the signal generator RF output, PTT the PA and increase the generator output (Don’t exceed +24 dBm) whilst measuring the output power output (≥50watts@ +25dBM ).
- Page 36 MX920 Base Station & Repeater Technical Manual This page left blank intentionally 2003 Revision...
-
Page 37: Alignment And Testing
Technical Manual Installation and Operation 7. Alignment and Testing The MX920 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. 7.1 Transceiver Setup, Calibration and Alignment This section explains how to setup, calibrate and align the complete MX920 Base Station. -
Page 38: Setting Ctcss/Dcs
MX920 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 or in hardware via the front channel select. The MX920 comes from the factory pre-aligned, so in most cases adjustment will not be required. -
Page 39: Temperature Calibration
Technical Manual Installation and Operation 7.1.7 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 MX920 Base Station. -
Page 40: Tx Centre Frequency Alignment
MX920 Base Station & Repeater Technical Manual Adjust the Reference Deviation digital potentiometer until the top of the waveform is flat. If the waveform top droops increase the level (see Figure 7-1) and if it peaks reduce the level (see Figure 7-2). Repeat steps 5 through to 9 until the correct peak deviation and modulation balance is obtained. -
Page 41: Microphone Line Input Level
Technical Manual Installation and Operation 7.1.11 Microphone Line Input Level (Nominal Deviation Or Peak Deviation Mode) The required nominal deviation or Peak deviation is dependent on whether the radio is narrow or wide. The following table lists the required level for each case: Bandwidth FM Nominal FM Peak... -
Page 42: Appendices
MX920 Base Station & Repeater Technical Manual 8. Appendices 8.1 MX920 Interface Connections The user connections to the MX920 are all made via the Front and rear panel where the following connectors are located. Conn Type Function Description Location for internal simplex relay. The N TYPE Simplex relay out or N type RX input... -
Page 43: Cn6 Simplex Relay
Technical Manual Installation and Operation 1 ....8 Figure 8-1 RJ45 socket viewed from front of MX920 8.1.1 CN6 Simplex Relay This option maybe also pre-installed or retrofitted at a later date. The N type connector for the RX port is removed and the relay is mounted in it’s position, which then acts as the RF I/O port for simplex operation. -
Page 44: Mx920 Test Points
MX920 Base Station & Repeater Technical Manual MX920 Test Points Test Points Function Volts Notes/ Condition Discriminator 2.5V 1Vp-P RX Audio Limiter output TX Audio Limiter output 15Volts VCO Supply 15.5V Supply Rail For VCO Control Volts 8 Volts Supply Regulator Output IC38 PA Refl Volts <200mV... -
Page 45: Establishing Rs232 Communications
Technical Manual Installation and Operation 8.3 Establishing RS232 Communications In this section we will look at how to connect your personal computer (PC) to the MX920, allowing access to the powerful inbuilt menu system. The RS232 programming port is part of the front Panel Microphone accessory socket. You will be required to make a RS232 cable to be able to communicate with the in built menu system software in the MX920. -
Page 46: Software Menu System
MX920 Base Station & Repeater Technical Manual Figure 8-2 Front veiw of DB9 female connector and RJ45 Modular male connector Figure 8-3 RS232 Cable 8.3.1 Software Menu System The MX920 Desktop Repeater comes with its own internal menu system accessed with any general terminal package. -
Page 47: Interfacing Information
Technical Manual Installation and Operation 8.3.2 Interfacing Information The RS-232 signal on a single cable is impossible to screen effectively for noise. By screening the entire cable we can reduce the influence of outside noise, but internally generated noise remains a problem. So when an audio connection and a RS232 Control are required at the same time, use a double adaptor RJ45 socket (Figure 1-1). -
Page 48: General
MX920 Base Station & Repeater Technical Manual 8.4.2 General Parameter Specification MX920 Rack Size: 3RU Tray, 330mm deep including fan. MX920 Overall Physical Size 89mm high, 360mm deep, 483mm wide Weight < 9 kg Supply Voltage: 13.8V +/- 20%. Power Consumption: <400mA receive, typical 360mA. -
Page 49: Transmit
Technical Manual Installation and Operation 8.4.3 Transmit Measured in accordance with TIA/EIA-603 standards. Parameter Specification RF Power Output: 1W to 50W Frequency Stability: > 300 MHz 1.5PPM for –10 to 60C, 2.5PPM for –30 to –10C < 300 MHz 2.5PPM for –10 to 60C, 5PPM for –30 to –10C. Audio response: Flat within +1, -3 dB across bandwidth Audio Bandwidth VF input:... -
Page 50: Receive
MX920 Base Station & Repeater Technical Manual 8.4.4 Receive Measured in accordance with TIA/EIA-603 standards. Parameter Specification Sensitivity: Better than –117 dBm for 12 dB SINAD. Typical –120 dBm. Selectivity 135-520MHz: More than 85 dB for 25 kHz adj channel. More than 75 dB for 12.5 kHz adj channel. -
Page 51: Mx920 Model Number Configuration Guide
Technical Manual Installation and Operation 8.5 SMX920 Model Number Configuration Guide The SMX/SDMX920 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. SDMX92 SMX92 0 –...