Page 1 SPECTRA ENGINEERING PTY Base Station, Repeater, Receiver and Transmitter MX800 Technical Manual...
Page 3 Web: www.spectraeng.com.au Manual Revision 4.2.3 August 2006 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. All performance figures quoted are typical and are subject to normal manufacturing and service tolerances.
Page 4 MX800 Transceiver Technical Manual This page left blank intentionally © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 5 MX800 Transceiver 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: Safety Summary
2. Operation in locations subject to abnormal environmental conditions such as extreme temperatures or ingress of moisture. 3. Operation of the MX800 Transmitter output into an open or short circuit or an incorrectly terminated load. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 7: Table Of Contents
Installation ..............23 T05 Balanced and Isolated VF plus E&M .........25 3.5.1 Description..............25 3.5.2 Installation ..............26 T06 Simplex Changeover Relay ..........27 3.6.1 Description..............27 3.6.2 Installation ..............28 T07 Turn Around Mixer.............29 T08 VF Delay................30 3.8.1 Description..............30 © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 8 T31 Network Adapter..............63 3.19.1 Optional Dongles ............64 3.19.2 U72 Dongle ..............64 3.19.3 U73 Dongle with Digital IO Port Replicator....64 3.20 T34 Ethernet option..............65 Technical Description................66 Exciter Module................66 Receiver Module ................67 Power Amplifier Module ............69 © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 9 Exciter Module ..............83 5.2.2 Receiver Module............84 5.2.3 Power Amplifier Module ..........86 5.2.4 VCO Board..............87 5.2.5 Microcontroller Module..........88 MX800 Base Station Fault Finding Procedure........90 MX800 Base Station ..............90 6.1.1 Transmitter Section ............90 6.1.2 Receiver Section ............91 Microcontroller PCB..............92 Receiver Module ................92 6.3.1 VCO Locking..............92...
Page 10 7.2.2 General................105 7.2.3 Transmit ..............106 7.2.4 Receive ................107 7.2.5 Ancillaries ..............108 Channel Select DIP Switch Settings ........108 MX800 Model Number Configuration Guide......112 MX800 System Applications ...........113 7.5.1 Conventional base station/repeater ......113 7.5.2 Link transceiver............113 7.5.3 Data transceiver............114 7.5.4 Paging transmitter............114 7.5.5...
Page 11 Table 3-4 Option PCB Link Settings.................33 Table 3-5 Current Consumption Details ..............35 Table 3-6 Option PCB Link Settings.................35 Table 3-7 MX800 Mic Socket Pinout................41 Table 3-8 Signal decision levels/points and coresponding tones......52 Table 3-9 CN3 Connections..................58 Table 3-10 CN9 Connections..................59 Table 3-11 T19/26 Factory Default Jumper Setting.
Page 12 Figure 3-2MX800 DCS Option T03................21 Figure 3-3 CN9 RJ45 Pin-out Detail (View from Rear of MX800) ......23 Figure 3-4 MX800 Option T05 Balanced & Isolated VF I/O with E&M leads..25 Figure 3-5 CN9 RJ45 Pin-out Detail (View from Rear of MX800) ......26 Figure 3-6 T06 Simplex Changeover Relay...............27...
Page 13: General Description
Power Amplifier are contained in their own specialised aluminium module and can be easily removed from the main chassis. The flexibility of the MX800 series allows it to be configured for a wide range of applications. Standard MX800 applications include:...
Page 14 Trunking control and VF routing interface Built in community multi-tone style repeater High stability reference input for Simulcast systems In addition, the MX800 can be fitted with many options, not being limited to the following: Programmable channel spacing Programmable CTCSS / DCS encoder and decoder Isolated VF and E&M lead interfaces...
Page 15: Physical Description
Module, a Power Amplifier Module and a Micro Controller board. These modules are housed in a fully welded steel case. The MX800 features a high degree of RFI and EMI screening throughout the design and construction. The receiver and exciter (low power transmitter) modules are contained in solid aluminium enclosures, and for additional screening each interface pin in the modules is individually filtered.
Page 16: Figure 1-1 Standard Front Panel
For each switch closure the volume is incremented or decremented a fixed amount. Newer versions of the MX800 Micro Controller PCB support a conventional rotary volume control. The newer versions are also backward compatible in that the...
Page 17 Option and omit others. For example operating channel select from the front panel may not be required (or permitted) and the Local Control Option may be ordered without this feature Refer to section 3. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 18: Rear Panel
CN7 BNC Rx Input CN8 N-Type Thermally N-Type Rx Input Power Input or External Ref Input TX Output Controlled Fan When fitted CN9 RJ45 CN1 Line When fitted Digital I/O RS232 Monitor Figure 1-3 MX800 Rear Panel © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 19: Side Panel
Technical Manual General Description 1.1.2 Side Panel The MX800 side view is illustrated in Figure 1-4 below. Two mounting holes in each side make provision for fitting a slider rail bracket. Mounting Holes for Slide Rails Sideways Airflow Permits MX800s...
Page 20: Receiver Module
Micro Controller. The PA is very compact and efficient for high reliability and low cost. The heatsink has minimal temperature rise even under continuous operation, ensuring the best MTBF obtainable for a practical design. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 21: Micro Controller Board
The circuit board has an onboard EEROM in which is stored all of the user channel related data such as frequencies, CTCSS tones etc. A serial port at the rear (or optionally the front) of the MX800 provides access to the Controller card and in conjunction with the Spectra Engineering "MXTOOLS"...
Page 22 MX800 Transceiver Technical Manual This page left blank intentionally © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 23: Installation And Operation
0.5V volt drop at this current. 2.2 Operation The MX800 can operate in local control mode via the front panel controls, stand alone repeater mode, or may be remotely controlled through the line port. Setting up the MX800 to operate in the wanted mode is straightforward and involves four main steps.
Page 24: Mxtools Utility
MX800 Networking See New Option T31 & T34 also. At sites where more than one MX800 is located it is possible to "bus" the RS232 lines to allow up to 16 MX800s at one site to be addressed on a single RS232 port.
Page 25: Setting To Work
Technical Manual Technical Description 2.2.2 Setting to Work The following sections describe the steps necessary to set the MX800 to operate as required. 2.2.2.1 Setting Micro Controller Jumpers The micro controller layout is contained in the drawing section and the position of the jumpers and DIP switches (highlighted) are shown below.
Page 26 Disables TX VF to line and TTR VF. The function polarity or nil can be selected. JMP 19 Selects either internal pull up to Pull up 5V or internal pull down to ETH for digital input on D25 connector © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 27: Table 2-1 Micro Controller Jumpers
Table 2-1 Micro Controller Jumpers When the MX800 option card is not fitted there is no connection made to SKK (Aux 2 connector) on the micro controller. Links should be placed across SKK1-2 (Discriminator audio), SKK11-12 (TX supply) and SKK13- 14 (RX supply).
Page 28: Table 2-2 Dip Switch 2 Settings
If the switch is ON and the channel is programmed as a repeater channel (using MXTOOLS) the MX800 will act as a repeater. If the switch is OFF the MX800 will remain in full duplex mode even if the channel is programmed as a repeater. The Simplex Enable operates in a similar way.
Page 29 2.2.2.4 Configure Alarms/M Lead The MX800 has 3 open collector outputs. Two of these are assigned as alarm outputs and one (output 1) may be configured as either an alarm output or an M Lead output. If the output one is configured as an M Lead, this line is active when mute is open and CTCSS/DCS is decoded.
Page 30: Adjustments
2.2.2.5 Configure Digital I/O The MX800 has 16 digital inputs and 8 general-purpose outputs. The inputs are +5V CMOS logic compatible and are buffered by a 10K resistor in series with each input. JMP19 on the Micro-Controller selects whether these inputs are internally pulled up or internally pulled low.
Page 31: Options
3.1 T01 Programmable Channel Spacing 3.1.1 Description The MX800 receiver is available in five different channel spacing options. For applications in systems that require both 12.5kHz and 25kHz channel spacing option T01 allows channels to be programmed for either bandwidth.
Page 32: T02 Programmable Ctcss Encoder/Decoder
3.2 T02 Programmable CTCSS encoder/decoder 3.2.1 Description Provision is made in the MX800 to fit a CTCSS encoder/decoder. The decoder is non-predictive and any valid CTCSS tone can be decoded. Any standard TX CTCSS tone may be associated with the programmed decode tone through the Channel Edit screen in MXTOOLS.
Page 33: T03 Programmable Dcs/Ctcss Encoder/Decoder
3.3.1 Description Provision is made in the MX800 to fit a full duplex DCS encoder/decoder. There are 83 digital codes available. Any standard DCS code or CTCSS tone may be assigned to any of the transmit or receive channels through the Channel screen in MXTOOLS.
Page 34: T04 Balanced And Isolated Vf
DCS code in the TX and/or RX channel fields. MX800 Testing: 1. If the MX800 had a CTCSS Option previously fitted, test the radio for correct operation of the DCS Option in both the Transmit and Receive modes.
Page 35: Installation
600ohm balanced TX VF leg b Table 3-1 CN9 Connections The RJ45 pins are numbered as shown in Figure 3-3 below. 1 ....8 Figure 3-3 CN9 RJ45 Pin-out Detail (View from Rear of MX800) Refer circuit diagram CS018-1 3.4.2 Installation Components Required: 1.
Page 36 1. Remove the cover to the MX800 radio. 2. Remove the rear connector label from the back panel of the MX800. 3. Punch out the small indented rectangle on the rear LHS of the MX800. 4. Remove the connectors from the Motherboard headers SKE, SKF and SKH.
Page 37: T05 Balanced And Isolated Vf Plus E&M
E lead (JMP1 in position 1-2) then the normally closed contact is also available at CN9. The relay contacts are rated at 500mA. Figure 3-4 MX800 Option T05 Balanced & Isolated VF I/O with E&M leads Pin No...
Page 38: Installation
Method: As for Option T04 (see section 3.4.2) MX800 Testing: 1. Connect a Communications Test Set via the RIB to the MX800 balanced audio RJ45 connector as per paragraph 3.4 of the MX800 Technical Manual. 2. Set the switches on the RIB to measure balanced audio and E&M.
Page 39: T06 Simplex Changeover Relay
Technical Manual Technical Description 5. PTT the MX800 and measure the TX modulation depth. Adjust RV4 or RV4A for the modulation depth that is require if necessary. 6. To check the Rx isolated mute output, switch the RF level on the Comm.’s test set to ON.
Page 40: Installation
Take extreme care to not over-tighten the screws and prevent stripping of the threads in the relay body. 8. Install the relay Assy into the MX800 with the relay coil on the opposite side of the relay to the DC power connector. Secure with the 2 of 3x8mm screws provided.
Page 41: T07 Turn Around Mixer
11. Replace the rear connector label with the label supplied. MX800 Controller Setup: 1. The MX800 RF channels that are required to be simplex should be programmed as ‘SIMPLEX’ within the channel edits screen of Mxtools and then downloaded to the MX800.
Page 42: T08 Vf Delay
(by the data controller) the VF to line and air can be disconnected for the duration of the data burst thus avoiding radio system user annoyance. Internal switches in the MX800 may be used to disconnect the audio under the control of the RX TALK line (CN1 Pin7) the sense of which may be inverted using JMP12 on the micro controller.
Page 43: Installation
Qty-4 Test Equipment Required: 1. Communications Test Set 2. MX800 Radio Interface Box Method: Remove the cover to the MX800 radio. Remove qty4 of the Motherboard securing screws as shown. Motherboard 3x5mm machine screws to be removed Install the qty 4 3x20mm standoff posts into the vacant screw positions.
Page 44: T09 300Hz Upgrade Hpf Filter
2. Download the Configuration change to the MX800. MX800 Testing: 1. Connect a Communications Test Set via the RIB to the MX800. 2. Set the switches on the RIB to Line Audio and E&M. 3. Set the test set to measure Rx line level and ensure that the Receiver is operating correctly.
Page 45: Installation
Qty-4 Test Equipment Required: 1. Communications Test Set 2. MX800 Radio Interface Box Method: 1. Remove the cover to the MX800 radio. 2. Remove qty4 of the Motherboard securing screws as shown. Motherboard 3x5mm machine screws to be removed © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 46: T10 Power Save Mode
3.10 T10 Power Save Mode 3.10.1 Description For solar powered sites and other power critical applications the MX800 is capable of a Power Save (Low Standby Current) Mode. This option can be implemented in three stages. Stage one implementation replaces the micro controller linear voltage regulators with switching regulators.
Page 47: Table 3-5 Current Consumption Details
Technical Manual Technical Description Approx Average Condition Description Current Drain mA Standard Standard MX800 (TX VCO on continuously) Standard Standard MX800 (TX VCO switched) Stage 1a Standard MX800 (TX VCO on continuously) option board fitted Stage 1b Standard MX800 (TX switched) option board...
Page 48: Installation
1. Remove the cover to the MX800 radio. 2. Remove the Motherboard from the MX800 radio. 3. Remove IC’s 21 and 27 from the Motherboard. 4. Reinstall the Motherboard into the MX800 radio and using the qty 4 3x20mm standoff posts in the positions indicated below: Motherboard...
Page 49: T11 Combined Options
3. Download the Configuration change to the MX800. MX800 Testing: Connect a Communications Test Set via the RIB to the MX800. Set the switches on the RIB to Line Audio and E&M. Check that all the Transmit parameters (i.e. TX power, modulation, freq.
Page 50: Installation
1. Communications Test Set 2. MX800 Radio Interface Box Method – MX800 Chassis: 1. Remove the cover to the MX800 radio. 2. Remove the ribbon cable from the Exciter module. 3. Remove the coaxial cable Assy from the Exciter module.
Page 51 2. Download the Configuration change to the MX800. MX800 Testing: 1. Connect a Communications Test Set via the RIB to the MX800. 2. Set the switches on the RIB to Line Audio and E&M. 3. Connect the External Reference source to the MX800 BNC connector.
Page 52: T13 Local Speaker, Mic Socket And Front Panel Mute
Panel Mute 3.13.1 Description For applications needing a user interface at the base station the MX800 is available with the Local Control option. The full implementation is described in section 1.1.1.2 this section describes the part fitted under option T13.
Page 53: Installation
Table 3-7 MX800 Mic Socket Pinout The RJ45 pins are numbered as shown in Figure 3-4 below. 1 ....8 Figure 3-9 RJ45 socket viewed from front of MX800 Refer circuit diagram CS001-6 sheet 6 of 6 3.13.2 Installation CAUTION:...
Page 54 1. Communications Test Set Jumper link Installation Method – MX800 Chassis: 1. Remove the cover to the MX800 radio. 2. Remove the motherboard from the chassis. 3. Remove the Exciter and receiver modules from the chassis by unscrewing the 2 M4x35mm screws on each module.
Page 55 2. Connect Dummy load to MX800 RF out put (CN8) 3. Connect the MX800 Rx input to the RF out (or Duplex out) of the CTS. 4. Set-up the CTS for operation with the audio generator set to 1kHz @ -10 dBm and the audiometer to show Audio input level.
Page 56: T14 Local Channel Change
3.14 T14 Local Channel Change 3.14.1 Description For applications needing a user interface at the base station the MX800 is available with the Local Control option. The full implementation is described in section 1.1.1.2, this section describes the part fitted under option T14.
Page 57 2. Download the configuration change to the MX800. MX800 Testing: 1. Connect a Communications Test Set and the RIB to the MX800. 2. Set the switches on the RIB to Line Audio and Line E&M. 3. Set MXTOOLS into Diagnostics mode and ‘Start’ the diagnosis process.
Page 58: T16 1Ppm Frequency Stability
4. Change the channel on the local channel switches and check that the channel selected on the BCD switch is in fact the channel that the Diagnostics screen indicates. 5. Reset the MX800 operating channel to the required position. 3.15 T16 1PPM Frequency Stability 12.5kHz channels Frequency band K to X (320-950MHz) 25.0kHz channels Frequency band R to X (805-950MHz)
Page 59: T19/26 Line Interface Board
Technical Manual Technical Description 3.17 T19/26 Line Interface Board. The MX800 T19 / T26 option board provides the radio base station with utmost flexibility in system design and capabilities, with an extensive range of new features. Please consult Spectra, for the availability of these features or software upgrades.
Page 60: Figure 3-10 Mx800 T19/T26Option Board
MX800 Transceiver Technical Manual Figure 3-10 MX800 T19/T26Option Board Due to ongoing development please refer to www.spectraeng.com.au for the latest information regarding this option. Note These are software selectable provided the correct option board is selected/used, and not all option can be used in conjunction with each other.
Page 61: Installation
Note# When installing cables insure that they are fitted with the correct orientation. Method: 1. Remove the cover to the MX800 radio. 2. Remove mother board from chassis of radio. Note cable connection and orientation. 3. Install the CABLE IDC SKT-IDC SKT 10W 330mm...
Page 62 14. Remove and replace CN4 with CABLE IDC DB15F-IDC SKT 16W 210mm cable Assy. Connect to SKH/B on the Option board. 15. Check that the option board jumpers are in the correct positions for application. 16. See the appropriate application section for Setup procedure. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 63: 2Wire Or 4Wire Selection, Balanced Vf
Internal switches in the MX800 may be used to disconnect the audio under the control of the RX TALK line (CN1 Pin7) the sense of which may be inverted using JMP12 on the micro controller.
Page 64: Variable & Stepped Tone Encoder
3.17.4.2 Voting Law The table below shows the default voting decisions points programmed into the MX800 T19 / T26 option board. These are the corresponding signal points where by under control of the microprocessor to generates the appropriate audio tone.
Page 65 This is done through the menu system using options ‘R’ then ‘C’. The user will then be prompted to turn off the receiver signal source to initiate the calculations. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 66: Variable Tone Setup Procedure
6. Press the Escape Key. RX Alignments 1. Using a 600ohm termination monitor RX line output level. This output is located on the rear of the MX800, RJ45 Line I/O connector pin 1 & 2 (balanced audio) 2. Remove JMP20 3.
Page 67: Status Tone Encoding And Decoding (T19 Only)
This power full option board allow the user to be able to monitor the status of the MX800. This option works by superimposing fixed audio tones per status to line. Providing status on mute open or closed. This signal then can be send down a 2 or 4 wire line system.
Page 68 RX Alignments 1. Using a 600ohm termination monitor RX line output level. This output is located on the rear of the MX800, RJ45 Line I/O connector pin 1 & 2 (balanced audio) 2. Set the receiver modulation frequency to 1kHz and the FM deviation to nominal for the particular RF receive frequency of the test channel.
Page 69: Five Tone Encoded / Decoder
This option is not currently available. Due to ongoing development please refer to www.spectraeng.com.au for the latest information regarding this option. 3.17.10 Fast CTCSS Decoder This option is not currently available. Due to ongoing development please refer to www.spectraeng.com.au for the latest information regarding this option. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 70: T19/26 Pinouts
INPUT PORT B. BCD Channel Select Tens bit 2. / Binary Bit 6. INPUT PORT B. BCD Channel Select Tens bit 3. / Binary Bit 7. Table 3-9 CN3 Connections Figure 3-11 CN3 Pin-out Detail (View from Rear of MX800) © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 71: Table 3-10 Cn9 Connections
E1 Lead leg a/M lead normally closed E1 Lead leg b Table 3-10 CN9 Connections The RJ45 pins are numbered as shown below. 1 ....8 Figure 3-12 CN9 RJ45 Pin-out Detail (View from Rear of MX800) © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 72: T19/T26 Jumper Settings
RX DISC Audio Break Point JMP27 TX Audio Break Point Connected JMP28 AGC Ratio NF (Unlinked) JMP29 RS232 Swap JMP30 RS232 Swap JMP31 D-A Section path RX/TX N/F (Unlinked) Table 3-11 T19/26 Factory Default Jumper Setting. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 73: T29 Balanced And Isolated Vf Plus E&M
E lead (JMP3 in position 1-2) then the normally closed contact is also available at CN9 pin 8. The relay contacts are rated at 500mA. Figure 3-13 MX800 T29 otpion board © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 74: Table 3-12 T29 Rj45 Pin Outs
E Lead leg a/M lead normally closed E Lead leg b Table 3-12 T29 RJ45 Pin outs. 1 ....8 Figure 3-14 CN9 RJ45 Pin-out Detail (View from Rear of MX800) Factory Default setting Position 2-3 Not fitted Position 2-3 Not fitted Table 3-13 T29 Factory Default Jumper Setting.
Page 75: T31 Network Adapter
The T31 board intercepts the serial data port of the MX800 encoding and decoding the external data stream, converting it to/from standard MX800 data required by the MX800 Micro-controller board.
Page 76: Optional Dongles
3.19.1 Optional Dongles There are two different dongles available that can be plugged directly into CN3 (T31’s DB44) to allow external selection of the MX800’s operating channel and it’s T31 network address. The dongles can be set and be used as...
Page 77: T34 Ethernet Option
The T34 includes a web server to output web pages for analysing the health of the host MX800 using a standard HTML web browser. The T34 board intercepts the serial data port of the MX800 and converts the MX800 data to and from IP packets that are transferred over the Ethernet link.
Page 78: Technical Description
Technical Manual 4. Technical Description The internal design of the MX800 is of a modular nature allowing for simple configuration and maintenance while ensuring minimal downtime. For reference purposes, the top view of a typical MX800 with top cover removed is shown in Figure 4-1 below.
Page 79: Receiver Module
IC12 is a broadband high performance MMIC with a gain of 18dB, noise figure of 3dB and 3rd order intermodulation intercept of +36dB. A 4dB pad and a second 3 section BPF follow this, and a high level double balanced mixer M1. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 80 This signal switches the supply to the local oscillator amplifier and is used to enable or disable the receiver. Provision is made for the optional injection of an external reference frequency. If this option is selected CN3 is fitted. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 81: Power Amplifier Module
Technical Manual Technical Description 4.3 Power Amplifier Module The MX800 now supports Spectra Engineering new full switching bandwidth Power Amplifier Module (Wide Band PA). Which requires no tuning, equals, exceeds or covers several of Spectra’s band allocations, (refer to section 7.4 for details of the band allocations).
Page 82: Overall Radio Management
In addition to the synthesiser programming bus an I C bus goes to each of the modules. This bus is currently unused. IC25 is a non-predictive, full duplex CTCSS encoder/decoder, which is under the control of the microprocessor. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 83: Tx Signal Processing
VCO and the reference oscillator. A third digipot is used to provide an offset null for the reference oscillator centre frequency. Adjustment of these levels is also by way of MXTOOLS using the Channel Edit screen. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 84: Rx Signal Processing
PWM1 output is progressively increased and the filtered result of this forms a ramp to the top of the power control digipot. Once 100% duty cycle is reached full power is produced. This results in a fast but controlled RF power rise characteristic. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 85: User Interface
Technical Description 4.4.5 User Interface All user interfaces to the MX800 except the RF connections is made by way of the Micro Controller board. Output latch IC18 drives the six LED indicators on the front panel. The function is described in section 1.1.1.
Page 86: Alignment And Testing
5.1 Transceiver Setup, Calibration and Alignment This section explains how to setup, calibrate and align the complete MX800 Base Station. A number of procedures are required to fully initialise the MX800. The following test equipment will be needed:...
Page 87: Sending Configuration Information
If an existing radio already contains the desired configuration then this configuration can be downloaded and saved. This configuration information then needs to be ‘Sent to the MX800’. A warning message will appear that indicates that the MX800 Base Station has not yet been calibrated, this may be ignored.
Page 88: Power Calibration
The RSSI calibration is used to calibrate the RSSI meter on the MXTOOLS Diagnostics Screen. The procedure requires an RF signal generator and the relevant leads to connect the signal generator to the RF input of the MX800 Base Station. RSSI calibration is done via the MXTOOLS Calibration Screen.
Page 89: Peak Deviation And Modulation Balance
400Hz. The transmitter modulating audio for this test is connected to the WB/DC-FM input with JMP8 set to 1-2. This input is located on the rear of the MX800, on the Line I/O connector pin 13 of the DB15F connector. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 90: Figure 5-1 Under (Increase Level)
Examples of incorrect, observed waveforms are as follows: Figure 5-1 Under (increase level) Figure 5-2 Over (decrease level) The waveform when correctly aligned should look as follows: Figure 5-3 Correctly Aligned Waveform © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 91: Tx Centre Frequency Alignment
Alignment and Testing Choose ‘OK’ to accept the changes made and then from the Channel Screen choose ‘Send Data to MX800’. This then saves the changes that you have made to the radio. After balancing and setting the correct peak deviation is necessary to align the reference oscillator and re-check the deviation alignment, as the reference oscillator alignment affects the deviation.
Page 92 MX800 Transceiver Technical Manual JMP8 set to 1-2. This input is located on the rear of the MX800, on the Line I/O connector pin 13 of the DB15F connector Procedure: 1. PTT the transmitter. 2. Set the transmitter modulation frequency to 1kHz, 1Vp-p injected in through the WB/ DCFM input, CN1 pin13 with JMP8 set to 1-2.
Page 93 RX. (See Table 5-2 Nominal Deviation). Note The test channel must be programmed as a repeater channel so this potentiometer can be setup. If not then temporarily alter the channel settings using the Channel Edit Screen in MXTOOLS. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 94: Rx Line Output Level Adjustment
Disable the repeater (switch SW4/DIP2 OFF). Using a 600ohm termination monitor RX line output level. This output is located on the rear of the MX800, on the Line I/O connector pin 15 of the DB15F. Set the receiver modulation frequency to 1kHz and the FM deviation to nominal for the particular RF receive frequency of the test channel.
Page 95: Module Level Test Procedures
PC with MXTOOLS is connected to the radio. There are four modules in the MX800 - the Exciter, Receiver, Power Amplifier and Micro Controller. The Exciter and the Receiver have VCO daughter boards.
Page 96: Receiver Module
VCO and Reference oscillator modulation inputs. 5.2.2 Receiver Module Test Equipment: Tested MX800 with Receiver removed Tested RX VCO board (in wanted band) PC with MXTOOLS software RF Communications test set Spectrum analyser with tracking generator Multimeter High frequency (89.545MHz) pick up loop.
Page 97 23. Inject an RF signal at -80dBm with standard modulation at F into CN5, monitor line RX out and adjust T1 and T2 for minimum distortion. Reduce RF signal level and check that sensitivity is better than -112dBm for 12dB SINAD. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 98: Power Amplifier Module
25. Remove PA top cover. Measure resistance of thermistor between CN4- 6 and CN4-4, this should be approximately 2kΩ. Connect DC power lead and 10-way connector from MX800. Connect PA RF output to RF power meter and PA RF input (CN1) to RF signal generator.
Page 99: Vco Board
CN4-8 and CN4-5 again. These should now both read lower approximately 1V. Remove PTT. 5.2.4 VCO Board Test Equipment: Tested MX800 with Exciter VCO removed PC with MXTOOLS software RF Communications test set Multimeter Oscilloscope +13.8VDC power supply Preliminaries: Program upper, middle and lower frequencies of band (refer section 5.4 for...
Page 100: Microcontroller Module
Technical Manual 5.2.5 Microcontroller Module Comprehensive testing of the Micro Controller can only be carried out at the Factory. The procedures in sections 5.1.10 to 5.1.13 provide alignment instructions for the workshop adjustable parameters. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
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Page 102: Mx800 Base Station Fault Finding Procedure
10 (Earth) & 12 (PTT) of CN1 the 15-way connector at the rear of the radio to ground. If the output power of the MX800 is LOW then using MXTOOLS check that the ‘Transmit Power’ control is not on a low setting.
Page 103: Receiver Section
SNR, Audio Distortion and Mute operation. Refer Section 6.3. If there is no audio signal, inject the test signal directly into the RX module and re-test for an audio signal on the MX800 test jig. Replace the RX input coax cable if faulty.
Page 104: Microcontroller Pcb
IC12 is approx. 8V. If the supply is OK, then replace IC12. If this does not repair the receiver then the alignment may be incorrect or other components on the front end may be faulty. Go to Section 5.2.2. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 105: If Section
If all the above tests pass then the VCO or IC10 may be faulty. Return the Exciter Module to your nearest Customer Service Centre. 6.4.2 RF Power Using MXTOOLS increase the ‘Transmit Power’ control to maximum and check that the output power is greater than +24 dBm. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 106: Power Amplifier
(Don’t exceed +24 dBm) whilst measuring the output power output (≥55watts@ +24dBM ). If all the above tests didn’t pass then the TR1 or TR2 may be faulty. Return to your nearest Customer Service Centre © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 108: Appendices
Technical Manual 7. Appendices 7.1 MX800 Interface Connections The user connections to the MX800 are all made via the rear panel where the following connectors are located. Conn Type Function Description DB15-F Line I/O Provides the necessary analog receiver and transmitter interface for system interfacing.
Page 109: Cn1 Db15 Female Line I/O Connector
JMP18 or place it in position 1&2. TX PTT IN. (E-LEAD). The standard PTT input is active low and may be driven from standard +5V logic outputs or open collector © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 110: Table 7-2 Cn1 Connections
JMP17. RECEIVER AUDIO 600Ω. Receiver audio output from op-amp. Default nominal line level is set to -10dBm. Unbalanced output with common return to analog Earth. Table 7-2 CN1 Connections © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 111: Cn2 Db9 Female Monitor Connector
CN2 DB9 Female Monitor Connector This port provides monitor and test functions for the MX800. It may be optionally located on the front panel of the MX800. The functions of the pins are described in Table 7-3 below. Pin No Function EARTH.
Page 112: Cn3 Db25 Female Digital I/O Connector
OUTPUT PORT C. 8-bit Logic Output bit 2. (Digital CTCSS Control bit 2) OUTPUT PORT C. 8-bit Logic Output bit 1. (Digital CTCSS Control bit 1) OUTPUT PORT C. 8-bit Logic Output bit 0. (Digital CTCSS Control bit 0) Table 7-4 CN3 Connections © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 113 Technical Manual Appendices Note When the front panel channel select option is fitted, input port should not be used from the external connector CN3 as it is wired to the thumbwheel switch. © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 114: Cn4 Db9 Male Rs232 Connector
7.1.4 CN4 DB9 Male RS232 Connector RS232 serial port to the MX800. It may be optionally located on the front panel of the MX800. Only 3 wires are required for the MX800 TXD, RXD and ground. The function of TXD and RXD pins can be interchanged by changing jumpers JMP10 and JMP11.
Page 115: Cn5 Dc Power Input
0.5V drop at 10A for the required length of the lead. PIN No Function Unused Ground + 13.8VDC Table 7-6 CN5 DC Power Input Connections Figure 7-1 CN5 DC Input (View from rear of MX800) © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 116: Mx800 Specifications
7.2.1 Operating Frequency Bands The MX800 is available in a number of models, which cover the range of operating frequency bands. As the transmitters and receivers are functionally independent the radios may be cross-banded if required. Refer to section 7.4 for details of the band breakdown.
Page 117: General
50kHz, 30kHz, 25kHz, 20kHz or 12.5kHz. Synthesiser Step Size: 25, 12.5,10, 7.5 or 6.25kHz. Channels: 255 Software, DIP switch and rear port selectable.1- 99 through rear port if configured for BCD parallel selection. Table 7-7 General Specifications © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 118: Transmit
RF Switching Bandwidth PA: Band dependent , typ >35Mhz Duty Cycle: 100% for 50W RF output with thermally controlled fan. RF Rise Time: 4mS with continuous VCO selected (Controlled RF envelope). Table 7-8 Transmit Specifications © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 119: Receive
Audio Bandwidth VF output: 300Hz to 3000Hz, +1/-3dB Squelch Opening Time: Less than 20mS @ 20dB SINAD. Squelch Closing Time: Less than 100mS. Conducted Spurious: Less than -57dBm, typ -90dBm. Table 7-9 Receive Specifications © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 120: Ancillaries
If a hardware channel select method is chosen the following table shows how to set the switches for each channel. Select the fixed channel for the MX800 by using the DIP switch DIP1 located on the Micro Controller Board. Channel 1 to 255 is available in binary selection.
Page 124: Mx800 Model Number Configuration Guide
Technical Manual 7.4 MX800 Model Number Configuration Guide The MX800 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.
Page 125: Mx800 System Applications
7.5.2 Link transceiver In the UHF bands (400 to 520 MHz) the MX800 is available in 1W and 50W. The 1W version being intended for link transceiver application. Transmit and receive audio is conveniently brought out to the D15 connector on the rear of...
Page 126: Data Transceiver
CTCSS signal is available at the RX leg of the link to recover the tone. Hence the Analog CTCSS tone can be transferred (or cross banded) from one MX800 to another. On an RF path with good signal to noise ratio, this enables CTCSS synchronization across the link in the situation where multiple tone group operate at two different sites.
Page 127: Trunking Base Station
LTR trunking systems make use of a digital sub audible signalling scheme. Once again the low frequency modulation capabilities (down to DC) of MX800 are vital in ensuring that the signalling takes place and a low bit error rate. A marginal system will result if the Transmitter modulation response can not go below 10Hz.
Page 128: Duplicated Base Station
3.18 7.5.12 Voting base station As noted in section 3.17 the MX800 with option to T19 can provide a Variable tone encoder. This encoder is compatible with a commonly used Variable tone-voting arbitrator.
Page 129 The use of this feature and a low frequency carrier dithering has proven to eliminate the previous requirements of extremely high stability reference frequency inputs. The MX800 has been widely installed for the use in simulcast systems. These DSP based systems provide automatic compensation for changes in modulation delay characteristics.
Page 130 MX800 Conventional repeater Systems MX800 Transceiver TITLE MX800 Conventional Systems Examples Portables and mobiles units SPECTRA ENGINEERING PTY LTD DRAWN AJCC DOC No SC001-1A CHECKED SHEET 1 0F 1 DATE 08/03/04 APPROVED...
Page 131 Two MX800 Conventional repeater Systems linked together (Back To Back Repeaters) Two MX800 Conventional repeater Systems linked together via a RF link using MX800 TITLE MX800 Conventional Systems Examples SPECTRA ENGINEERING PTY LTD DRAWN AJCC DOC No SC001-2A CHECKED SHEET...
Page 133 Example of system configuration 2 or 4 Wire Line Interface E & M Controlled by Tones or Isolated interface MX800 MX800 Fitted with Fitted with T19/T26 option Boards T19/T26 option Boards SITE A SITE B Portables and mobiles units Portables and moblie units...
Page 135 MX800 MX800 0 to 5V POCSAG signal to DC FM Modem input. MX800 uses repeater PTT. TX only MX800 Repeat VF source set to Line. MX800TX V23 FSK tones PTT active low 5V Cmos compatible Modem Digital POCSAG bit stream...
Page 136 Bridge This section illustrates and This section illustrates and This section illustrates a MX800 repeater connected to MX800 connected to a link MX800 connected to a link two link transceivers. For this type of connection and transceiver. All that is required transceiver.
Page 138: Superseded Technical Information
TR2 serves to switch the DC supply to the Hybrid under control of the PTT line from the Micro Controller on CN4-2. A thermistor TS1, physically located on the PA heatsink to monitor the heatsink temperature, is connected to the Micro Controller via CN4-4/6 © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 139: Pa Module Test Procedure
Remove PA top cover. Measure resistance of thermistor between CN4- 6 and CN4-4, this should be approximately 2kΩ. Connect DC power lead and 10-way connector from MX800. Connect PA RF output to RF power meter and PA RF input (CN1) to RF signal generator.
Page 140: Pa Fault Finding Procedure
The hybrid may be faulty if it has an output of less than 5W. The PA RF transistor may be faulty if the hybrid has an output power of greater than 5W. See section 9.1 for superseded PA Drawings © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 142: Drawings
N to Q CS031-1 Wide Band Power Amplifier 50W Circuit Diagram A to B CS033-1 Wide Band Power Amplifier 50W Circuit Diagram K to M CS035-1 T29 isolated interface Circuit Diagram CS037-1 T19/T26 Line encoder/decoder interface © SPECTRA ENGINEERING 2006 Revision 4.2.2...
Page 143: Superseded Drawings
DCS option PCB EV0001-1 MX800 Transceiver Final Assembly EV0002-1 MX800 PA Sub-Assembly EV0003-1 MX800 Rx & Exciter Module Sub-Assembly EV0004-1 MX800 Internal Power Cable Assembly Table 9-1 Drawings 9.1 Superseded Drawings Consult Spectra Engineering regarding obtain Superseded Drawings. Drawing No.
Page 144: Figure 9-1 Receiver Component Overlay
MX800 Transceiver Technical Manual Figure 9-1 Receiver Component Overlay © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 145: Figure 9-2 Exciter Component Overlay
Technical Manual Drawings Figure 9-2 Exciter Component Overlay © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 146 MX800 Transceiver Technical Manual Figure 9-3 PA Component Overlay - Figure 9-4 PA Component Overlay –New Superseded Version Wide Band PA Version © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 147: Figure 9-5 Micro Controller Component Overlay (Rev P4)
Technical Manual Drawings Figure 9-5 Micro Controller Component Overlay (Rev P4) © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 148: Figure 9-6 Tx And Rx Vco Component Overlay Bands A To Q3
MX800 Transceiver Technical Manual Figure 9-6 Tx and Rx VCO Component Overlay Bands A to Q3 © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 149: Figure 9-7 Tx And Rx Vco Component Overlay Bands R To X
Technical Manual Drawings Figure 9-7 Tx and Rx VCO Component Overlay Bands R to X © SPECTRA ENGINEERING 2006 Revision 4.2.3...
Page 150: Figure 9-8 Hp Rx Vco Component Overlay Bands A To Q
MX800 Transceiver Technical Manual Figure 9-8 HP Rx VCO Component Overlay Bands A to Q © SPECTRA ENGINEERING 2006 Revision 4.2.3...

Spectra Engineering MX800 Technical Manual

1 General Description

2 Installation and Operation

3 Options

4 Technical Description

5 Alignment and Testing

6 MX800 Base Station Fault Finding Procedure

7 Appendices

8 Superseded Technical Information

9 Drawings

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