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800MHz & VHF Cell Enhancers

Maintenance Handbook

H/book Number:-50-078001HBKM

Issue No:-

Date:-02/09/2004

Page:-

1 of 88

24 Channel 800MHz

& VHF Cell Enhancers

Maintenance Handbook

For

Terry Consulting

AFL Works Order N.: Q111353

AFL product part N’s.: 50-078001 (800 & VHF CE’s)

80-209302 (Battery Back-up)

Summary of content (88 pages)

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24 Channel 800MHz & VHF Cell Enhancers Maintenance Handbook For Terry Consulting AFL Works Order Nō.: Q111353 AFL product part Nō’s.
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Table of Contents AMENDMENT LIST RECORD SHEET .................................................................................................. 6 INTRODUCTION ....................................................................................................................................... 7 Scope...........................................................................................................................................................................7 Purpose.............................
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5. SUB-UNIT MODULES .................................................................................................................. 49 5.1 Bandpass Filters (02-007201 & 01-002503)..............................................................................................49 5.1.1 Description ...............................................................................................................................................49 5.1.2 Technical Specification (02-007201) .........................
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5.17 3 Stage Alarm PCB & 3 Stage Simplex Alarm PCB(12-002201 & 12-002203) ....................................66 5.17.1 Description ...........................................................................................................................................66 5.17.2 Technical Specification ........................................................................................................................67 5.17.3 Generic Summary Alarm Wiring Sketch .........................................
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7.3 Care of Modules .........................................................................................................................................86 7.3.1 General Comments ...................................................................................................................................86 7.3.2 Module Removal (LNA’s, general procedure): .......................................................................................86 7.3.3 Module Replacement (general): ....................
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AMENDMENT LIST RECORD SHEET Issue Nō. A Date 14/09/2004 Incorporated by CMH Page No.
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INTRODUCTION Scope This handbook is for use solely with the equipment identified by the AFL Part Number shown on the front cover. It is not to be used with any other equipment unless specifically authorised by Aerial Facilities Limited. This is a controlled release document and, as such, becomes a part of Aerial Facilities’ Total Quality Management System. Alterations and modification may therefore only be performed by Aerial Facilities Ltd.
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Glossary of Terms Repeater or Cell Enhancer Band Selective Repeater Channel Selective Repeater BTS C/NR Downlink (D.L.) Uplink (U.L.) EMC GND DC AC ID OIP3 LED M.S. N/A N/C NF RF Rx Tx S/N A Radio Frequency (RF) amplifier which can simultaneously amplify and re-broadcast Mobile Station (MS) and Base Transceiver Station (BTS) signals. A Cell Enhancer designed for operation on a range of channels within a specified frequency band.
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Key to AFL RF Module Drawing Symbols 800MHz & VHF Cell Enhancers Maintenance Handbook H/book Number:-50-078001HBKM Issue No:-A Date:-02/09/2004 Page:-9 of 88
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1. SAFETY CONSIDERATIONS 1.1 Earthing of Equipment Cell Enhancers supplied from the mains must be connected to grounded outlets and earthed in conformity with appropriate local, national and international electricity supply and safety regulations. 1.2 Electric Shock Hazard Electrical shocks due to faulty mains driven power supplies.
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1.3 RF Radiation Hazard RF radiation, (especially at UHF frequencies) arising from transmitter outputs connected to AFL’s equipment, must be considered a safety hazard. This condition might only occur in the event of cable disconnection, or because a ‘spare’ output has been left unterminated. Either of these conditions would impair the system’s efficiency. No investigation should be carried out until all RF power sources have been removed.
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1.4 Chemical Hazard Beryllium Oxide, also known as Beryllium Monoxide, or Thermalox™, is sometimes used in devices within equipment produced by Aerial Facilities Ltd. Beryllium oxide dust can be toxic if inhaled, leading to chronic respiratory problems. It is harmless if ingested or by contact. Products that contain beryllium are load terminations (dummy loads) and some power amplifiers. These products can be identified by a yellow and black “skull and crossbones” danger symbol (shown above).
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2. OVERVIEW/SYSTEM DESCRIPTION The AFL Channel and/or Band Selective Cell Enhancers are 2-way on-band repeaters. Various models are available to cover frequency bands from 50MHz to 3000MHz. The principle sphere of applications is in urban areas where the topology is such that shadows occur in the propagation pattern (for example within large buildings, conference centres, road and rail tunnels, etc.) The frequency bands that are passed by the Cell Enhancer are set as per the specific customer requirements.
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3. SPECIFICATION 3.P Photographs 3.P.
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3.P.
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3.P.
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3.P.
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3.P.
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3.P.6 VHF Simplex Shelf 50-078010 There are two different types of simplex shelves 50-078010/1 & 50-078010/2, they differ only in the frequencies they process.
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3.P.7 VHF Duplex Shelf 50-078011 There are four different types of duplex shelves 50-078011/1,2,3 & 4 they differ only in the frequencies they process.
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3.P.8 VHF Air Interface Shelf 50-078012 Photos of this shelf are unavailable.
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3.P.
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3.P.
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3.P.
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3.P.
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800MHz & VHF Cell Enhancers Maintenance Handbook H/book Number:-50-078001HBKM Issue No:-A Date:-02/09/2004 Page:-26 of 88
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800MHz & VHF Cell Enhancers Maintenance Handbook H/book Number:-50-078001HBKM Issue No:-A Date:-02/09/2004 Page:-27 of 88
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800MHz & VHF Cell Enhancers Maintenance Handbook H/book Number:-50-078001HBKM Issue No:-A Date:-02/09/2004 Page:-28 of 88
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3.1 Electrical Specification PARAMETER Frequency range: Bandwidth: Gain: Gain Adjustment: Uplink Power: Downlink Power Uplink Downlink Noise Figure: AGC: VSWR: RF Connectors: operational: Temperature range storage: IP3: Alarms Fitted: (non-latching, volt-free relay contacts/TTL) SPECIFICATION 851-869MHz (Downlink) 806-824MHz (Uplink) 160.2-161.8MHz (Simplex/Duplex) 18MHz (UHF) 1.6MHz (VHF) >100dB (Uplink) >90dB (Downlink) 0 - 30dB (in 2dB steps) >5.0Watts (UHF) >5.0Watts (VHF) >40.0Watts (UHF) >5.
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3.2 Channel Frequency Listing Channel No.
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3.3 Mechanical Specifications 3.3.1 Rack Mounted Equipment Mechanical Specifications PARAMETER Height: Rack Width: Depth: Height: Shelves: Width: Depth: operational : storage: Weight: Humidity: RF Connectors: Environmental Protection: Case: Heatsinks: Finish: Handles: Fascias Temperature Range: * 3.3.2 SPECIFICATION 40U Standard Eurorack 19" (482.6mm) 600mm (800 optional) See parts lists 19" (482.
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3.4 3.4.1 Parts Lists Whole System Parts List (50-078001) AFL Part Nō. 50-078002 50-078003 50-078004 50-078010/1 50-078010/2 50-078011/1 50-078011/2 50-078011/3 50-078011/4 50-078012 50-078013 50-078014 50-078015 50-078017 60-020608 80-209302 Part Description 800MHz AIR I/F + BSCE UPLINK SHELF 800MHz 8CH CHANNEL MOD.
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3.4.2 800MHz AIF Uplink Shelf 50-078002 Parts List AFL Part Nō.
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3.4.3 800MHz 8 Channel, Channel Module Shelf 50-078003 Parts List AFL Part Nō.
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3.4.4 800MHz 40W Amplifier Shelf 50-078004 Parts List AFL Part Nō. 02-007201 05-002602 10-000901 11-005802 12-018002 14-000225 50-012820 50-012822 50-012825 50-027720 80-090822 80-310420 91-030002 91-510032 91-520001 91-520005 91-520010 91-600007 91-600014 91-600015 91-660001 96-300057 96-700034 96-700035 96-900018 97-400005 99-200008 99-200017 Part Description 900MHz 8POLE 10-20MHz B/W SMA 900MHz SPLITTER/COMBINER, 20W SW. ATTENUATOR 0.
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3.4.5 VHF Simplex Shelf 50-078010/1 AFL Part Nō. 08-930002 10-000901 11-001202 12-002213 12-002220 12-002804 12-002820 12-004902 13-001803 13-001822 13-002811 17-001201 17-002802 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-540035 93-980109 96-110001 96-300014 96-700017 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.6 VHF Simplex Shelf 50-078010/2 Parts List AFL Part Nō. 08-930002 10-000901 11-001202 12-002213 12-002220 12-002804 12-002820 12-004902 13-001803 13-001822 13-002811 17-001201 17-002802 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-540035 93-980112 96-110001 96-300014 96-700017 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.7 VHF Duplex Shelf 50-078011/1 Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002201 12-002203 12-002220 12-004902 13-001803 13-001822 13-002812 17-001105 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-980103 93-980104 96-110001 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.8 VHF Duplex Shelf 50-078011/2 Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002201 12-002203 12-002220 12-004902 13-001803 13-001822 13-002812 17-001105 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-980105 93-980106 96-110001 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.9 VHF Duplex Shelf 50-078011/3 Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002201 12-002203 12-002220 12-004902 13-001803 13-001822 13-002812 17-001105 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-980107 93-980108 96-110001 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.10 VHF Duplex Shelf 50-078011/4 Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002201 12-002203 12-002220 12-004902 13-001803 13-001822 13-002812 17-001105 17-009135 19-000826 19-000921 19-000924 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-980110 93-980111 96-110001 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
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3.4.11 VHF Air Interface Shelf 50-078012 Parts List AFL Part Nō. 01-002503 05-002901 05-003401 07-005401 11-004802 12-002801 13-001803 19-000826 19-000921 80-024203 80-063627 91-030002 91-500001 91-510003 91-700017 93-540035 96-110001 96-700034 96-700035 97-400005 Part Description FILTER VHF H/B 6 SMA S 100W 3dB BROADBAND SPLITTER SMA 1WATT 4 WAY SPLITTER LOW POWER 160-470MHz 3 WAY SPLITTER 450MHz (10dB GAIN) LNA 12V.
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3.4.13 VHF PSU Shelf 50-078014 Parts List AFL Part Nō. 13-003301 20-001602 80-008920 80-008921 80-008922 80-008925 80-020632 91-500025 91-510004 91-510035 91-520001 91-520005 91-520010 91-520032 91-600015 91-800014 94-100004 96-100001 96-300054 96-600001 96-700035 96-900017 97-400002 Part Description MAINS FILTER 8AMP ASSEMBLY 24V RELAY BOARD DUAL PSU HEATSINK DUAL PSU CASE DUAL PSU LID DUAL PSU FRONT PANEL 2U CHASSIS LID FIXING RAIL 3 PIN RIGHT ANGLE FREE PLUG NC-X 3 PIN PNL.
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3.4.15 800Mhz In-Line Amplifier (Wall-Mount Case) 50-078017 Parts List AFL Part Nō.
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3.4.16 12V 160Ahour Battery Back-Up 80-209302 Parts List AFL Part Nō.
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94-100004 96-000004 96-100004 96-100006 96-110015 96-110042 96-300057 96-700002 96-700005 96-900018 96-920002 96-920008 96-920011 96-920012 97-100047 97-300010 97-400010 97-900004 99-200003 99-200008 99-200017 STPS12045TV 60A DUAL DIODE 38AH 12V S.L.A. BATTERY 32mm 20A FUSE HOLDER FUSE HOLDER ATO IN-LINE T 15A A/SURGE FUSE 1.25' 15A ATO FUSE 15V 27A PSU 400W (XP BCC) LED.GREEN 5mm SEALED IP66 LED.RED 5mm SEALED IP66 AC TRIP SWITCH (5 AMP M.C.B.
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H/book Number:-50-078001HBKM +25dBm A LC DET +26dBm Issue No:-A Date:-02/09/2004 26dBm 0dB 0dB 0dB 0dB 0dB 0dB 0dB 0dB dB 17-009127 17-009127 17-009127 17-009127 17-009127 17-009127 17-009127 17-009127 0dB 0dB 0dB 0dB 0dB 0dB 0dB 0dB dB 8 CHN M ODUL E 50-078003 17-009127 17-009127 17-009127 17-009127 17-009127 17-009127 17-009127 dB dB 0dB 0dB dB 0dB 0dB 0dB 0dB dB dB dB dB dB dB 50-078011 50-078011 0dB 0dB dB dB 0dB dB S QL S QL 0dB 800MHz
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4.
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5. SUB-UNIT MODULES 5.1 5.1.1 Bandpass Filters (02-007201 & 01-002503) Description The bandpass filters are multi-section designs with a bandwidth dependent upon the passband frequencies, (both tuned to customer requirements). The response shape is basically Chebyshev with a passband design ripple of 0.1dB. The filters are of slot coupled, folded combline design, and are carefully aligned during manufacture in order to optimise the insertion loss, VSWR and intermodulation characteristics of the unit.
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5.2 5.2.1 900MHz Splitter/Combiner (05-002602) Description The Splitter/Combiner used is a device for accurately matching two or more RF signals to single or multiple ports, whilst maintaining an accurate 50Ω load to all inputs/outputs and ensuring that the VSWR and insertion losses are kept to a minimum. Any unused ports will be terminated with an appropriate 50Ω load. Being passive devices, the splitters should have an extremely long operational life and require no maintenance.
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5.3 5.3.1 1 Watt 3dB Broadband Splitter (05-002901) Description The 1 Watt, 3dB Splitter/Combiner used is a device for accurately matching two or more RF signals to single or multiple ports, whilst maintaining an accurate 50Ω load to all inputs/outputs and ensuring that the VSWR and insertion losses are kept to a minimum. Any unused ports will be terminated with an appropriate 50Ω load. 5.3.
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5.4 5.4.1 Four Way Splitter (05-003302) Description The Splitter/Combiner used is a device for accurately matching two or more RF signals to single or multiple ports, whilst maintaining an accurate 50Ω load to all inputs/outputs and ensuring that the VSWR and insertion losses are kept to a minimum. Any unused ports will be terminated with an appropriate 50Ω load. 5.4.
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5.6 5.6.1 3 Way Splitter/Combiner (05-003801) Description The 3 way Splitter/Combiner used is a ‘Zinger’ type design for accurately matching three RF signals to a single port, whilst maintaining an accurate balance between ports, and ensuring that the VSWR and insertion losses attain the best possible specification. They are specialist passive devices and must be replaced in the unlikely event of failure. 5.6.
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5.7 Wideband 3dB Splitter (07-004101) 5.7.1 Description This wideband, 2 way hybrid splitter, is an AFL stock item with many years of reliable service. The successful construction of such a device, relies largely on a pcb developed within a rigid specification, skilled assembly and testing. Insertion loss quoted is a typical figure, any unit will be within 5% of this figure. 5.7.
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5.8 5.8.1 VHF/UHF 3-Way Splitter (07-005401) Description The 3dB Splitter/Combiner used is a device for accurately matching two or more RF signals to single or multiple ports, whilst maintaining an accurate 50Ω load to all inputs/outputs and ensuring that the VSWR and insertion losses are kept to a minimum. Any unused ports will be terminated with an appropriate 50Ω load. 5.8.
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5.9 5.9.1 3 Port Tx Hybrid Coupler (80-024203) Description The transmitter hybrid couplers provide isolation from unwanted reflected frequencies to/from the leaky feeder antennas. They are specialist narrow-band 3 port devices, designed with rejection and power handling as the main criteria. Being passive devices, the hybrid couplers should be maintenance free over their entire lifetime and have an extremely high MTBF figure.
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5.10 Crossband Coupler (07-005705) 5.10.1 Description The purpose of a crossband coupler is to either combine/split transmission signals from different parts of the frequency spectrum. The crossband coupler fitted here, is the means by which the separate VHF and UHF frequency band signals are mixed to form a composite RF signal. It basically comprises of a 3 port device, two filters, one a low pass the other a high pass, that are then mixed and fed to a common output.
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5.11 6dB Power Monitor (07-014002) 5.11.1 Description The purpose of these couplers is to tap off known portions (usually 3-30dB) of RF signal from transmission lines, either resistively or by induction, and to combine them, for example through splitter units for different purposes (alarms/monitoring etc.), whilst maintaining an accurate 50Ω load to all ports/interfaces throughout the specified frequency range.
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5.12 2-Port RF Isolator (08-930002) 5.12.1 Description The purpose of fitting an isolator to the output of a transmitter in a multi-transmitter environment is such that each output is afforded a degree of isolation from every other. Were this not to be the case, two simultaneous transmissions could interfere to create intermodulation products, especially in the non-linear power amplifier output stages of the transmitters.
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5.13 ¼Watt 0- -30dB & 0-15dB Variable Attenuators (10-000701 & 10-000901) 5.13.1 General Application In many practical applications for Cell Enhancers etc., the gain in each path is found to be excessive. Therefore, provision is made within the unit for the setting of attenuation in each path, to reduce the gain. 5.13.2 Switched Attenuators The AFL switched attenuators are available in two different types; 0 – 30dB in 2 dB steps, or 0 – 15dB in 1 dB steps.
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5.14 LNA’s (11-001202, 11-005802, 11-005902 11-006002, 11-006702 & 11-004802) 5.14.1 Description The Gallium-Arsenide low noise amplifiers used in the unit are double stage, solid-state low noise amplifiers. Class A circuitry is used throughout the units to ensure excellent linearity and extremely low noise over a very wide dynamic range. The active devices are very moderately rated to provide a long trouble-free working life.
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5.14.4 Technical Specification (11-005802) PARAMETER Frequency Range: Bandwidth: Gain: 1dB Compression Point: OIP3: Input/Output Return Loss: Noise Figure: Power Consumption: Supply Voltage: Connectors: operational Temperature Range: : storage: Size: Weight: SPECIFICATION 800 – 960MHz <170MHz 14.5±0.5dB (typical) 30dBm 46dBm >18dB <2.7dB 510-540mA @ 24V DC 10-24V DC SMA female -10°C to +55°C -40°C to +70°C 90 x 55 x 30.2mm 280gm (approximately) 5.14.
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5.14.6 Technical Specification (11-006002) PARAMETER Frequency range: Bandwidth: Gain: 1dB Compression Point: 3rd order intercept: Input return loss: Output return loss: VSWR: Noise figure: Connectors: Supply: Size: operational: Temperature range: storage: Weight: SPECIFICATION 70 – 500MHz <430MHz 21dB (typical) +20dB (typical) +33dB (typical) >14dB >20dB Better than 1.5:1 <2.7dB SMA female 230 - 260mA @ 10 to 24V DC 88 x 50 x 34mm (ex. connectors) -10°C to +60°C -20°C to +70°C 0.26kg 5.14.
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5.15 5, 10 & 20W 900MHz Power Amplifiers (12-018601, 12-018001 & 12-018002) 5.15.1 Description These Gallium-Arsenide power amplifiers are Class A 10 & 20W power amplifier from 800-960MHz in a 1 stage balanced configuration. It demonstrates a very high linearity and a very good input/output return loss. It has built in a Current Fault Alarm Function with a volt-free relay contact pair as its output.
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5.15.4 Technical Specification (12-018002, 20W) PARAMETER Frequency range: Small signal gain: Gain flatness: I/O Return loss: 1dB compression point: OIP3: Supply voltage: Supply current: Temperature operational: range storage: Weight: 5.16 SPECIFICATION 800-960MHz 30dB ±1.2dB >18dB 42.8dBm 56dBm 12V DC 5.0Amps (Typical) -10°C to +55°C -30°C to +70°C <2kg (no heatsink) VHF 5Watt Power Amplifier (12-004902) 5.16.1 Description The power amplifier used is a triple stage solid-state low-noise amplifier.
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5.17 3 Stage Alarm PCB & 3 Stage Simplex Alarm PCB(12-002201 & 12-002203) 5.17.1 Description Amplifier Alarm Boards are fitted to monitor the bias conditions of AFL Class A amplifiers which remain constant in normal operation. Any departure from normal bias conditions is a result of device failure, excess temperature, over-driving or oscillation (excessive power). In normal operation, the Class A bias circuit of the amplifier develops a constant voltage of 1.
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5.17.2 Technical Specification PARAMETER SPECIFICATION Operating voltage: 8 to 30V (floating earth) Alarm Threshold: Vcc - 1.20 volt +15% Alarm output relay contacts: Max. switch current: 1.0Amp Max. switch volts: 120Vdc/60VA Max. switch power: 24W/60VA Min. switch load: 10.0µA/10.0mV Relay isolation: 1.5kV Mechanical life: >2x107 operations Relay approval: BT type 56 Connector details: 15-way 0.
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5.18 1 & 3 Stage Alarm/Simplex/Mute PCB (12-002804 & 12-002213) 5.18.1 Description In systems using simplex channel switching, it is necessary to be able to distinguish between a ‘normal’ switching operation and erroneous modes where faults in the detector circuitry may cause data errors but not necessarily fire the alarms. The simplex alarm/mute board is designed to differentiate between normal and spurious switching signals for single or multiple stage amplifiers. 5.
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5.20 Dual DC/DC Converter (13-001803) 5.20.1 Description This unit is employed where it is necessary to derive two fixed voltage power supply rails from some higher voltage. Typically it is used to derive 5, 8, 12 or 15V from a 24V input. The circuit is based upon a pair of LM257 series variable voltage regulators (LM2576, 12 & 15V & LM2575, 5V), which are each capable of supplying an absolute maximum of 1.5A output current.
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5.21 Simplex Squelch & AF Module (17-002802) 5.21.1 Description The difference in signal levels between the paths means that the channel modules would latch onto any signal in the band rather than a signal at the desired channel frequency. This is achieved, in part, to having the de-sense module, (which is controlled by the Simplex Rx squelch unit), apply maximum attenuation (via an AGC attenuator unit) to the downlink path, when the uplink is active. 5.21.
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5.22 Wide Dynamic Range (Log.) 12V AGC (17-001109, det. & 17-001201, atten.) 5.22.1 Description The equipment is fitted with a wide dynamic range (logarithmic detector) Automatic Gain Control (AGC) system. This is generally fitted in the Uplink path (not usually needed in the downlink path, as the signal here is at an almost constant level), to avoid overloading the input amplifiers should a mobile be operated very close to the unit.
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5.22.2 Technical Specification PARAMETER Frequency Range: Attenuation Range: Attenuation Steps: VSWR: RF Connectors: attenuator: Power Handling: detector/amp: operation: Temperature Range: storage: attenuator pcb Size: detector/amp pcb attenuator: Weight: detector/amp: SPECIFICATION up to 1000MHz 3 to 30dB continuously variable better than 1.
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5.23 Channel Control Module (17-002101) 5.23.1 Description The purpose of the channel control modules is to change the channel selective module frequencies by means of a series of D.I.P switch banks, each switch corresponding to a different ‘frequency bit’. 5.23.2 Technical Specification Below shows the pin assignments for each switch on a channel control module.
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5.23.3 900MHz Programming Procedure Check that the required downlink and uplink frequencies fall within the operational band limits of the Cell Enhancer. For each Downlink and Uplink channel frequency, subtract the appropriate synthesiser offset frequency from the required operational frequency and record the resulting local oscillator frequencies. Divide each Downlink and Uplink local oscillator frequency by the synthesiser channel spacing and check that the result is an integer (ie: no remainder).
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5.23.4 900MHz Programming Example Frequency required: 958.0 MHz Channel spacing: 25 kHz Synthesiser offset: 70 MHz The Local Oscillator frequency is therefore: 958.0 – 70 = 888 MHz Dividing the LO frequency by the channel spacing of 0.025 MHz: 888.0 = 35520 0.025 This is an integer value, therefore it is OK to proceed. Local Oscillator Frequency 888.
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5.24 Channel Selective Modules (17-009127 UHF, & 17-009135 VHF) 5.24.1 Description The channel selectivity module is employed when the Cell Enhancer requirement dictates that very narrow bandwidths (single operating channels), must be selected from within the operating passband. One channel selectivity module is required for each channel.
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5.24.2 Drg. Nō.
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5.25 12 & 24V Relay Boards (20-001601 & 20-001602) 5.25.1 Description The General Purpose Relay Board allows the inversion of signals and the isolation of circuits. It is equipped with two dual pole change-over relays RL1 and RL2, with completely isolated wiring, accessed via screw terminals. Both relays are provided with polarity protection diodes and diodes for suppressing the transients caused by "flywheel effect" which can destroy switching transistors or induce spikes on neighbouring circuits.
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5.26 12V Low Voltage Battery Disconnect Module (80-061003) 5.26.1 Description The low voltage disconnect module’s main function is to monitor the battery voltage as the batteries discharge. When a pre-set value has been reached (usually 21.5V DC) the unit will disconnect the batteries to prevent a ‘deep discharge’ state which, if allowed to continue, could irreparably damage the batteries, necessitating replacement.
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5.29 STPS12045TV 60A Dual Diode Assembly (94-100004) 5.29.1 Description The purpose of these dual diode assemblies is to allow two (or more) DC voltage sources to be combined, so that the main 12 or 24 volt DC rail within the equipment is sourced from either the mains driven flat-pack, or externally through an XLR connector on the rear panel. The heavy-duty diodes prevent any reverse current from flowing back to their source or the alternative supply rail.
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6. INSTALLATION 6.1 Initial Installation Record When this equipment is initially commissioned, please use the equipment set-up record sheet in Appendix A. This will help both the installation personnel and AFL should these figures be needed for future reference or diagnosis. 6.1.
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6.1.4 RF Connections All RF connections are made to the cable termination, located on the bulkhead at the rear of the equipment at floor level (rack equipment). Care must be taken to ensure that the correct connections are made with particular attention made to the base station Tx/Rx ports. In the event that the base transmitter is connected to the Rx output of the rack, damage to the equipment will be done if the base station transmitter is then keyed.
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7. MAINTENANCE 7.1 7.1.1 General Procedures Basic Fault Finding In the event that the performance of the system is suspect, a methodical and logical approach to the problem will reveal the cause of the difficulty. The System consists of modules fitted within an 8U shelf and housed within a standard 19” rack type cabinet. Transmissions from the main base stations are passed though the system to the mobile radio equipment; this could be a handheld radio or a transceiver in a vehicle.
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7.1.2 Downlink Confirm that there is a signal at the expected frequency and strength from the base station. If this is not present then the fault may lay outside the system. To confirm this, inject a downlink frequency signal from a known source at the master site BTS input and check for output at the remote site feeder output. If a signal is not received at the output it will be necessary to follow the downlink path through the system to find a point at which the signal is lost.
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7.1.5 Checking service Following the repair of any part of the system it is recommended that a full end-to-end test is carried out in accordance with the test specification and that the coverage is checked by survey. It is important to bear in mind that the system includes a radiating cable network and base stations that may be faulty or may have been damaged. 7.1.6 Service Support Advice and assistance with maintaining and servicing this system are available by contacting Aerial Facilities Ltd. 7.
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7.3 7.3.1 Care of Modules General Comments Many of the active modules contain semiconductor devices utilising MOS technology, which can be damaged by electrostatic discharge. Correct handling of such modules is mandatory to ensure their long-term reliability. To prevent damage to a module, it must be withdrawn/inserted with care. The module may have connectors on its underside, which might not be visible to the service operative. 7.3.
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5) If the amplifier to be removed has a heatsink attached, there may be several different ways it can have been assembled. The most commonly used method, is screws through the front of the heatsink to threaded screw holes (or nuts and bolts), into the amplifier within the main case. If the heatsink is mounted on the rear of the main case (e.g.
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APPENDIX A INITIAL EQUIPMENT SET-UP CALCULATIONS GENERAL INFORMATION Client Name: AFL Equip. Model Nō. Site Name: Date: Model ANTENNA SYSTEMS Gain Azimuth Comments Type Loss Comments A - Service Antenna B – Donor Antenna Length C – Service Feeder D – Donor Feeder INITIAL PARAMETERS E – CE Output Power F – Antenna Isolation G – Input signal level from donor BTS Operating Voltage DOWNLINK CALCULATIONS Parameter Comments Input signal level (G) CE max.