PBE Europe as Axell Wireless 60-1668SERIES UHF AIR Interface type 60-166801 User Manual 60 166801HBKM

Axell Wireless UHF AIR Interface type 60-166801 60 166801HBKM

User manual

Baltimore Transit Radio Repeater System User/Maintenance Handbook (4) forIntelect Corp. AFL Works Order: Q113737 AFL product part No.: 60-166801 Aerial Facilities Limited Technical Literature Baltimore Radio Repeater System Maintenance HandbookHandbook Number 60-166801HBKM Issue No. A Date 15/02/2006 Page 1 of 23
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 2 of 23 1. INTRODUCTION Scope and Purpose of this Document 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. AFL recommends that the installer of this equipment familiarise his/herself with the safety and installation procedures contained within this document before installation commences. The purpose of this handbook is to provide the user/maintainer with sufficient information to service and repair the equipment to the level agreed. Maintenance and adjustments to any deeper level must be performed by AFL, normally at the company’s repair facility in Chesham, England. This handbook has been prepared in accordance with BS 4884, and AFL’s Quality procedures, which maintain the company’s registration to BS EN ISO 9001:2000 and to the R&TTE Directive of the European Parliament. Copies of the relevant certificates and the company Quality Manual can be supplied on application to the Quality Manager. This document fulfils the relevant requirements of Article 6 of the R&TTE Directive. Limitation of Liability Notice This manual is written for the use of technically competent operators/service persons. No liability is accepted by AFL for use or misuse of this manual, the information contained therein, or the consequences of any actions resulting from the use of the said information, including, but not limited to, descriptive, procedural, typographical, arithmetical, or listing errors. Furthermore, AFL does not warrant the absolute accuracy of the information contained within this manual, or it’s completeness, fitness for purpose, or scope. AFL has a policy of continuous product development and enhancement, and as such, reserves the right to amend, alter, update and generally change the contents, appearance and pertinence of this document without notice. All AFL products carry a twelve month warranty from date of shipment. The warranty is expressly on a return to base repair or exchange basis and the warranty cover does not extend to on-site repair or complete unit exchange.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 3 of 23 Table of Contents 1. INTRODUCTION.......................................................................................................................... 2Scope and Purpose of this Document................................................................................................. 2Limitation of Liability Notice................................................................................................................. 22. SAFETY CONSIDERATIONS...................................................................................................... 42.1 Earthing of Equipment .............................................................................................................. 42.2 Electric Shock Hazard............................................................................................................... 42.3 RF Radiation Hazard ................................................................................................................ 42.4 Chemical Hazard ...................................................................................................................... 52.5 Laser safety .............................................................................................................................. 52.6 Emergency Contact Numbers................................................................................................... 53. EQUIPMENT OVERVIEW/SPECIFICATIONS............................................................................. 63.1 Off-Air (M.O.C.E) Remote Repeater (60-166801) .................................................................... 73.2 Off-Air (M.O.C.E) Remote Repeater Description................................................................... 73.3 Off-Air (M.O.C.E) Remote Repeater Technical Specifications .............................................. 73.4 Off-Air (M.O.C.E) Remote Repeater Mechanical Specifications ........................................... 73.5 Off-Air (M.O.C.E) Remote Repeater System Diagram, Drg. No. 60-166881......................... 83.6 Off-Air (M.O.C.E) Remote Repeater Alarm Wiring Details, Drg. No. 60-166851................... 93.7 MOCE Site UHF AIF BDA Outline Drawing, Drg. Nǀ. 60-166891 ....................................... 103.8 Off-Air (M.O.C.E) Remote Repeater Parts List (60-166801) ............................................... 114. INSTALLATION & COMMISIONING.......................................................................................... 124.1 Initial Installation Record......................................................................................................... 124.2 Antenna Installation & Gain Calculations................................................................................ 124.3 Antenna Isolation .................................................................................................................... 134.4 Rack Mounted Equipment.......................................................................................................144.5 Optical Connections................................................................................................................ 144.6 Wall Mounted Equipment........................................................................................................ 154.7 RF Connections ...................................................................................................................... 154.8 RF Commissioning.................................................................................................................. 155. FAULT FINDING / MAINTENANCE........................................................................................... 165.1 Tools & Test Equipment.......................................................................................................... 165.2 Basic Fault Finding ................................................................................................................. 165.3 Quick Fault Checklist .............................................................................................................. 175.4 Downlink ................................................................................................................................. 175.5 Uplink...................................................................................................................................... 175.6 Fault repair.............................................................................................................................. 175.7 Service Support ...................................................................................................................... 175.8 Care of Modules...................................................................................................................... 185.9 Module Removal (LNAs, general procedure):......................................................................... 185.10 Module Replacement (general): .......................................................................................... 185.11 Power Amplifiers.................................................................................................................. 185.12 Low Power Amplifier Replacement...................................................................................... 195.13 Module Transportation:........................................................................................................ 196 APPENDIXES ............................................................................................................................ 206.1 Glossary of Terms used in this document............................................................................... 206.2 AFL RF Module Drawing Key ................................................................................................. 216.3 EC Declaration of Conformity .................................................................................................226.4 Amendment List Record Sheet ............................................................................................... 23
2. SAFETY CONSIDERATIONS 2.1 Earthing of Equipment Equipment 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. 2.2 Electric Shock Hazard The risk of electrical shocks due to faulty mains driven power supplies whilst potentially ever present in any electrical equipment, would be minimised by adherence to good installation practice and thorough testing at the following stages: a) Original assembly. b) Commissioning. c) Regular intervals, thereafter. All test equipment must be in good working order prior to its use. High current power supplies can be dangerous because of the possibility of substantial arcing. Always switch off during disconnection and reconnection.2.3 RF Radiation Hazard RF radiation, (especially at UHF frequencies) arising from transmitter outputs connected to AFL’s equipment, must be considered a safety hazard. Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 4 of 23 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. This would always be a wise precaution, despite the severe mismatch between the impedance of an N type connector at 50, and that of free space at 377, which would severely mitigate against the efficient radiation of RF power. Radio frequency burns could also be a hazard, if any RF power carrying components were to be carelessly touched! Antenna positions should be chosen to comply with requirements (both local & statutory) regarding exposure of personnel to RF radiation. When connected to an antenna, the unit is capable of producing RF field strengths, which may exceed guideline safe values especially if used with antennas having appreciable gain. In this regard the use of directional antennas with backscreens and a strict site rule that personnel must remain behind the screen while the RF power is on, is strongly recommended. Where the equipment is used near power lines, or in association with temporary masts not having lightning protection, the use of a safety earth connected to the case-earthing bolt is strongly advised.
2.4 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). They are marked as hazardous in line with international regulations, but pose no threat under normal circumstances. Only if a component containing beryllium oxide has suffered catastrophic failure, or exploded, will there be any danger of the formation of dust. Any dust that has been created will be contained within the equipment module as long as the module remains sealed. For this reason, any module carrying the yellow and black danger sign should not be opened. If the equipment is suspected of failure, or is at the end of its life-cycle, it must be returned to Aerial Facilities Ltd for disposal.To return such equipment, please contact the Quality Department, who will give you a Returned Materials Authorisation (RMA) number. Please quote this number on the packing documents, and on all correspondence relating to the shipment. PolyTetraFluoroEthylene, (P.T.F.E.) and P.T.F.E. Composite Materials Many modules/components in AFL equipment contain P.T.F.E. as part of the RF insulation barrier. This material should never be heated to the point where smoke or fumes are evolved. Any person feeling drowsy after coming into contact with P.T.F.E. especially dust or fumes should seek medical attention.Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 5 of 23 2.5 Laser safety General good working practices adapted fromEN60825-2: 2004/ EC 60825-2:2004 Do not stare with unprotected eyes or with any unapproved optical device at the fibre ends or connector faces or point them at other people, Use only approved filtered or attenuating viewing aids. Any single or multiple fibre end or ends found not to be terminated (for example, matched, spliced) shall be individually or collectively covered when not being worked on. They shall not be readily visible and sharp ends shall not be exposed. When using test cords, the optical power source shall be the last connected and the first disconnected.Use only approved methods for cleaning and preparing optical fibres and optical connectors, do not allow any dirt/foreign material ingress on the optical connector bulkheads and always keep optical connectors covered to avoid physical damage. The optical fibre jumper cable maximum bend radius is 3 cm (1 ¼" ), any smaller radii may result in optical cable breakage or excessive transmission losses. Caution: Do not get the Fibre Optic units wet, they are NOT weather proof. 2.6 Emergency Contact Numbers The AFL Quality Department can be contacted on: Telephone +44 (0)1494 777000 Fax. +44 (0)1494 777002 e-mail mail to:qa@aerial.co.uk
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 6 of 23 3. EQUIPMENT OVERVIEW/SPECIFICATIONS The Baltimore repeater system consists of several items of hardware:- Master Site Preston UHF Air Interface Channelised Amplifier (60-166101, rack mounting) Master Site OCC UHF Air Interface Channelised Amplifier (60-166201, rack mounting) Preston Six-Way Fibre Optic Master Site (60-166301, rack mounting) OCC Six-Way Fibre Optic Master Site (60-166401, rack mounting) Remote Site High Power UHF Bi-Directional Amplifier (60-166501, wall mounting) MOCE Site Air Interface Repeater (60-166801, wall mounting) 6 x 114Ah Battery Backups (80-333201, wall mounting) There are two master sites, one at PRESTON and one at OCC, each has a 19” rack cabinet containing the four off-air receiving shelves, which also contain the power supplies and the DC/DC converters (12V) for the FO shelf.The master site equipment receives off-air transmissions which it channelises, (15 channels) and sends this downlink signal data to six fibre optic RX modules. Remotely sited cell enhancers receive this FO data, demodulate and amplify it and feed it to local LCX antennas. At the remote sites, the same leaky feeder antennas receive mobile signals, band selectively amplify them and send this uplink data back by FO to the master site where it is demodulated, channelised and broadcast on the same air interface antenna that received the downlink signal. Existing in the current system are bi-directional amplifiers in the 800MHz bands. These signals are catered for using specialist cross-band couplers so that the 800MHz signals bypass the 490MHz system path with negligible loss. 20dB couplers fitted at various points in the system ‘tap-off’ a signal suitable for monitoring the RF power in any path. Each active device is alarm monitored and these alarms are available either as separate volt-free relay contact pairs, in groups (e.g. all downlink power amplifiers), or as an alarm summary of the whole system with locally visible indications (LED’s). Six 114Ah battery backup systems ensure no loss of coverage should mains power fail. At the time of writing this document no information was available on which items of the system were to be fitted to the battery backups.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 7 of 23 3.1 Off-Air (M.O.C.E) Remote Repeater (60-166801) 3.2 Off-Air (M.O.C.E) Remote Repeater Description The off-air (M.O.C.E) repeater is linked to the master site by a dedicated antenna and has a low power (5Watts) downlink output to the mobile antenna. The repeater has an automatic gain control loop in each path to lessen the overloading effects of a mobile operated close to the uplink leaky feeder antennas. This unit also has its own mains-to-DC power supply or it can accept an external ‘DC in’ source (24V). A 100W, 12V DC/DC converter mounted in the repeater supplies all the DC needed for the amplifiers except for the 40Watt uplink power amplifiers which are supplied from 24V DC. A channel selective module with a wide bandwidth (1.25MHz, I.F.) is fitted in both paths to enable all 15 channels to be accommodated within a tightly controlled band. 3.3 Off-Air (M.O.C.E) Remote Repeater Technical Specifications PARAMETER SPECIFICATION494.3-495.3MHz (Downlink) Frequency range: 497.3-498.3MHz (Uplink) Number of channels 1Channel bandwidth: 1.25MHzRemote gain adjustment: 0-15dB (in 1dB steps) Rejection at opposing band: > 60dB Downlink1dB Compression Point: > +37.5dBm Downlink 3rd Order Intercept Point: > +50dBm Uplink 1dB Compression Point: > +47dBm Uplink 3rd Order Intercept Point: > +63dBm Noise Figure: <6.0dB at any gain setting Impedance: 50 ohmsRF Connectors: N type, female Power Supply: 110V AC (nominal) Power consumption: <8A ( @ 12V) operational: -10qC to +60qCTemperature range: storage: -40qC to +70qC3.4 Off-Air (M.O.C.E) Remote Repeater Mechanical Specifications PARAMETER SPECIFICATIONHeight: 820mmWidth: 620mmCase size Depth: 250mm(excluding heatsinks, connectors, handles and feet) Fixings: 4 holes on 670(w) x 775(h)mm operational: -10°C to +60°C Temperature range: storage: -40°C to +70°C Weight: 50kg (approximately)RF Connectors: N type female Environmental protection: IP65 (with door closed and all ports terminated) Case: Semi-gloss grey (RAL 7035) Heatsinks: Black anodised Finish:Handles: Black high impact technopolymer Supply Cable: Unit supplied with suitable supply input leads with connector and appropriate length of cable
3.5 Off-Air (M.O.C.E) Remote Repeater System Diagram, Drg. No. 60-166881 Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 8 of 23
3.6 Off-Air (M.O.C.E) Remote Repeater Alarm Wiring Details, Drg. No. 60-166851 Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 9 of 23
3.7 MOCE Site UHF AIF BDA Outline Drawing, Drg. Nǀ. 60-166891 Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 10 of 23
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 11 of 23 3.8 Off-Air (M.O.C.E) Remote Repeater Parts List (60-166801) AFL Part No. Part Description Qty. 02-013401 6 POLE SPECTRUM DIVIDING COMBLINE FILTER 405-002603 UHF 3dB SPLITTER 207-002902 POWER MONITOR 20dB OUTPUT 350-550MHz 207-002908 POWER MONITOR 30dB OUTPUT 350-550MHz 210-000901 SWITCHED ATTENUATOR 0-15dB 210-001205 REMOTE SWITCHED ATTENUATOR 0-15dB 111-007302 LOW NOISE AMPLIFIER 20dB GAIN 512-021601 AMPLIFIER 5W 112-021704 POWER AMPLIFIER (LINEARIZED ) 20W 212-021801 POWER AMPLIFIER 113-003011 DC-DC CONVERTOR BOARD 113-003301 MAINS FILTER 8AMP 117-000126 CELL ENHANCER ID LABEL 117-000526 GASKET FOR HEATSINK 217-001109 AGC UNIT DETECTOR 217-001201 AGC UNIT ATTENUATOR 217-001528 BLANKING PLATE GASKET 217-002020 CELL ENHANCER BODY 117-002021 EQUIPMENT MOUNTING PLATE 117-003042 CHANNEL MODULE 450-475MHz, 1.25MHz BW 220-001601 12V RELAY BOARD 420-001602 24V RELAY BOARD 180-031820 HEATSINK FOR 20W POWER AMPLIFIER 280-032320 HEATSINK FOR 10W POWER AMPLIFIER 180-310420 HEATSINK FOR POWER SUPPLY 190-100010 MAINS LEAD '6 AMP' FOR USA 190-200004 DC I/P LEADS, FREE SOCKET 191-030002 N ADAPTOR PANEL FEMALE:FEMALE 291-130001 SMA ADAPTOR 'T' ALL FEMALE 291-500011 3 POLE PANEL PLUG SEALED IP68 191-500013 2 POLE PANEL PLUG SEALED IP68 191-500015 CAP FOR PANEL PLUG 391-500043 25 POLE PANEL PLUG SEALED IP68 191-510037 25 POLE FREE SOCKET SEALED IP68 191-520033 25 POLE CONNECTOR SOCKET CONTACTS 2591-520034 25 POLE CONNECTOR PIN CONTACTS 2591-600014 'D' 9 WAY SOCKET 891-620001 'D' 25 WAY SOCKET 291-620006 D' 25 WAY CONNECTOR SHELL 291-640004 LARGE PIN FOR 7 WAY 2W5 MIXED D TYPE SOCKET 491-660001 7 WAY 2W5 MIXED D TYPE SOCKET 291-800003 10 WAY KRONE MODULE 293-930003 1W LOAD TERMINATION 296-110047 20A ATO FUSE 296-300054 POWER SUPPLY UNIT 400w 196-700034 LED RED 5mm IP67 196-700035 LED GREEN 5mm IP67 196-900018 AC TRIP SWITCH (5 AMP M.C.B.) 196-920037 THERMAL SWITCH 70c N/C 1A TO-220 197-000001 WALL MOUNTING BRACKETS 197-300010 MAINS SUPPLY INPUT COVER 297-300028 DC SWITCH AND FUSE BOX 197-400010 BLACK PLASTIC HANDLE 50mm HIGH 297-900004 RUBBER FOOT FOR CELL ENHANCER 4
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 12 of 23 4. INSTALLATION & COMMISIONING 4.1 Initial Installation Record When this equipment is initially commissioned, please use the equipment set-up record sheet in the Appendices. This will help both the installation personnel and AFL should these figures be needed for future reference or diagnosis. 4.2 Antenna Installation & Gain Calculations 1 Most Cell Enhancers require two antennas, one a highly directional Yagi or similar directed towards the donor cell base station, and one a leaky feeder, omni-directional antenna or Yagi to cover the area in which the mobiles are to be served. 2 The maximum gain at which the Cell Enhancer can be set is limited by the isolation that can be achieved between these two antennas. Therefore when the antennas have been installed, inject a signal (at a known power level) into one of them and measure the signal level received by the other antenna on a spectrum analyser. The isolation can then be calculated as the difference between these two figures. The gain in each path of the Cell Enhancer should be set at least 10 dB below this figure, using the switched attenuators as described below in paragraph 5. 3 Now measure the received signal from the donor cell at the input to the Cell Enhancer (base port). The gain of the Cell Enhancer downlink path should be set such that the donor site signal will not overload the Cell Enhancer amplifiers. It is recommended that the input level should be less than -50dBm at the input of the Cell Enhancer (Base port). (This figure is assuming maximum gain, and may be increased by the value of the attenuator fitted in the downlink path.) 4 Ensure that the mobile facing antenna has at least 70 dB isolation from the nearest mobile. (This is normally easily achievable when using a leaky feeder antenna, but usually requires positional adjustment when using a Yagi.) 5 The Cell Enhancer gain is fixed by setting the attenuation in each path (uplink and downlink) between the first two amplifier stages (see markings within the Cell Enhancer or layout drawings for the exact attenuator locations). Note that the uplink (mobile to base) and downlink (base to mobile) path gains are set independently. This allows the paths to have different gains if required to set the correct output power levels. The attenuation added into the path is a direct reflection of the active switch positions, i.e. switch 2 (2dB) and switch 4 (8dB) would add 10dB into the path. 6 It is recommended that the gains are set such that the Downlink channel output levels from the Cell Enhancer are typically +20dBm. (Input level + Gain = Output level).
4.3 Antenna Isolation A). First set up the two antennas & measure the isolation between them. Yagi Yagi or leaky feederMobilesMeasure Isolationbetween antennasBase site (donor)B). Install the Cell Enhancer with its gain set 10dB below the isolation figure obtained above. YagiYagi or leaky feederMobilesBMobile portBase portCell Enhancerase site (donor)Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 13 of 23
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 14 of 23 4.4 Rack Mounted Equipment The size and weight of the equipment racks mean that they represent a significant topple hazard unless they are bolted to the floor though the mounting holes in the base of the unit. In the interests of safety this should be done before any electrical, RF, or optical connections are made. The equipment must be located on a flat, level surface that is made from a material suitable for bearing the weight of the rack assemblies. If the installer is in any doubt about the suitability of a site it is recommended that he consult with an appropriately qualified Structural Engineer.It is important in determining the location of the rack within the room that space is allowed for access to the front and rear of the equipment. To enable maintenance to be carried out, the front doors of each rack must be able to open fully. In this AFL system, all RF, optical and power interfaces are located on the rear panels of the shelves; the cable interfaces to external equipment, mains, LCX feeds, fibre cables etc., is from the floor area. It is recommended that the mains supply connection is made by a qualified electrician, who must satisfy himself that the supply will be the correct voltage and of sufficient capacity. All electrical, optical and RF connections should be completed and double checked prior to power being applied for the first time. 4.5 Optical Connections The optical input and output ports will be located on the appropriate E/O shelf as shown in the rack layout drawing and the system layout drawing. The ports are supplied with a green plastic cover, which must be removed prior to the connection of the fibre cable. Ensure that transmitter and receiver fibre cable are identified to prevent misconnection. At the master site, the fibre transmitters are in the downlink path with the receivers in the uplink. At remote sites the fibre transmitters are in the uplink with the receivers in the downlink. Observe optical safety precautions in section 1. when handling fibre optic components. The individual fibre optic units are fitted with a pair of status indicators on their front panels. One is a green LED, which indicates that the unit is connected to a 12 Volt DC power supply. This indicator is common to both transmit and receive units. The second LED on the RX module indicates that the laser is operating (transmitting). On the RX unit the second LED indicates that a laser-light signal is being received. When all the fibre connections are completed and power to each site is connected each fibre unit must show two illuminated indicators. Ensure that connections are kept clean and are fully tightened.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 15 of 23 4.6 Wall Mounted Equipment The procedure for installing and commissioning a wall-mounted Bi-Directional Amplifier unit is generally as follows: 3 Fix the unit in the chosen position. Ensure the mounting site is a straight, smooth, perpendicular surface (brick or concrete recommended). Mounting bracket centres/dimensions will be found in the specifications section (3.3). After fixing, mechanically test the installation before proceeding. 4 Fix the two antennas (antenna isolation should already have been performed see section 4.2) and connect them to the BDA. 5 Connect a suitable mains and/or battery power supply to the unit. 6 Connect the alarm interface connectors. 7 Calculate the attenuation settings required for the uplink and the downlink paths, and set the attenuators as described elsewhere in this document. 8 Double-check all RF and power connections before switching the BDA mains on with the small switch located inside the unit on the lower right hand side of the case. 9 Alarms may not settle for several seconds after switch-on, but they should extinguish after a short time (up to 15 seconds). Make test calls via the equipment to ensure correct operation, if possible monitoring the signal levels during these calls to ensure that the uplink and downlink RF levels are as anticipated. 4.7 RF Connections Care must be taken to ensure that the correct connections are made with particular attention made to the optical TX/RX ports. Ensure that connections are kept clean and are fully tightened. 4.8 RF Commissioning Once all connections are made the equipment is ready for commissioning. To commission the system the test equipment detailed in Section 5.1 will be required. Using the system diagrams and the end-to-end test specification, the equipment should be tested to ensure correct operation. On initial power up the system alarm indicators on the front panels of the equipment should be checked. A red LED illuminated indicates a fault in that particular shelf that must be investigated before proceeding with the commissioning. A green LED on each shelf illuminates, to indicate that the power supply is connected to the shelf. In the event that any part of the system does not function correctly as expected, check all connections to ensure that they are to the correct port, that the interconnecting cables are not faulty and that they are tightened. The majority of commissioning difficulties arise from problems with interconnecting cables and connectors.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 16 of 23 5. FAULT FINDING / MAINTENANCE 5.1 Tools & Test Equipment The minimum tools and test equipment needed to successfully service this AFL product are as follows:- Spectrum analyser: 100kHz to 2GHz (Dynamic range = 90dB). Signal Generator: 30MHz to 2GHz (-120dBm to 0dBm o/p level). Attenuator: 20dB, 10W, DC-2GHz, (N male – N female). Test Antenna: Yagi or dipole for operating frequency. Digital multi-meter: Universal Volt-Ohm-Amp meter. Test cable x 2: N male – N male, 2M long RG214. Test cable x 2: SMA male – N male, 1m long RG223. Hand tools: Philips #1&2 tip screwdriver. 3mm flat bladed screwdriver. SMA spanner and torque setter. 5.2 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 separate modules in a wall-mounted enclosure. 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. This path is referred to as the downlink. The return signal path from mobile radio equipment to the base station is referred to as the uplink.The first fault finding operation is to check the alarms of each of the active units and determine that the power supplies to the equipment are connected and active. This can be achieved remotely (via CEMS, the RS232 Coverage Enhancement Management System, if fitted), or locally with the front panel LED’s. The green LED on the door should be illuminated, while the red alarm indicator should be off. If an alarm is on, then that individual module must be isolated and individually tested against the original test specification. The individual amplifier units have a green LED showing through a hole in their cover/lid, which is illuminated if the unit is working correctly. (Without active power supplies there can be no alarm LED indicators, however without DC power, the fail-safe summary alarm system [normally closed relay contacts] will be an open circuit, thereby activating any externally connected system.) If an amplifier is suspect, check the DC power supply to the unit. If no other fault is apparent use a spectrum analyser to measure the incoming signal level at the input and then after reconnecting the amplifier input, measure the output level. Consult with the system diagram to determine the expected gain and compare result. In the event that there are no alarms on and all units appear to be functioning it will be necessary to test the system in a systematic manner to confirm correct operation.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 17 of 23 5.3 Quick Fault Checklist All AFL equipment is individually tested to specification prior to despatch. Failure of this type of equipment is not common. Experience has shown that a large number of fault conditions relating to installations result from simple causes often occurring as result of transportation, unpacking and installation. Below are listed some common problems which have resulted in poor performance or an indicated non-functioning of the equipment. Mains power not connected or not switched on. External connectors not fitted or incorrectly fitted. Internal connectors/ports becoming loose due to transport vibration. Wiring becoming detached as a result of heavy handling. Input signals not present due to faults in the aerial and feeder system. Base transmissions not present due to faults at the base station. Modems fitted with incorrect software configuration/and or PIN No.’s. Changes to channel frequencies and inhibiting channels. Hand held radio equipment not correctly set to repeater channels. Hand held radio equipment not correctly set to base station. 5.4 Downlink Confirm that there is a signal at the expected frequency and strength from the base station(s). 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. 5.5 Uplink Testing etc. of the uplink paths is similar to the downlink paths, except for the frequencies involved. 5.6 Fault repair Once a faulty component has been identified, a decision must be made on the appropriate course to carry out a repair. A competent engineer can quickly remedy typical faults such as faulty connections or cables. The exceptions to this are cable assemblies connecting bandpass filter assemblies (duplexers) that are manufactured to critical lengths to maintain a 50-ohm system. Care should be taken when replacing cables or connectors to ensure that items are of the correct specification. The repair of component modules such as amplifiers and bandpass filters will not usually be possible in the field, as they frequently require specialist knowledge and test equipment to ensure correct operation. It is recommended that items of this type are replaced with a spare unit and the faulty unit returned to AFL for repair. 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 antennas and base stations that may be faulty or may have been damaged. 5.7 Service Support Advice and assistance with maintaining and servicing this system are available by contacting Aerial Facilities Ltd.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 18 of 23 5.8 Care of Modules 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. Good engineering practices should be observed at all times. To prevent damage to a module, it must be withdrawn/inserted with care. 5.9 Module Removal (LNAs, general procedure): The following general rules should be followed to remove a module: 1) Remove power to the unit 2) Remove all connectors (RF, DC/alarm) 3) Release module retaining screws. 4) Slowly but firmly, pull the module straight out of its position. Take care not to twist/turn the module during withdrawal. 5.10 Module Replacement (general): 1) Carefully align the module into its location then slowly push the module directly straight into its position, taking care not to twist/turn it during insertion. 2) Reconnect all connectors, RF, alarm, power etc. 3) Replace retaining screws (if any). 4) Double-check all connections before applying power. 5.11 Power Amplifiers 1) Remove power to the unit. (Switch off at mains/battery) 2) Disconnect multi-way alarm ‘D’ type connector 3) Carefully disconnect the RF input and output coaxial connectors (usually SMA) 4) 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., against a wall in the case of wall mounted enclosures), then the fixing method for the heatsink will be from within the case, (otherwise the enclosure would have to be removed from the wall in order to remove the heatsink). When the heatsink has been removed, the amplifier may be unscrewed from the main casing by its four corner fixings and gently withdrawn. Fitting a new power amplifier module will be the exact reverse of the above. Note: Do not forget to apply fresh heatsink compound to the heatsink/main case joint and also between the amplifier and the main case.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 19 of 23 5.12 Low Power Amplifier Replacement Disconnect the mains power supply and disconnect the 24V dc supply connector for the LPA. Disconnect the RF input and output cables from the LPA. Disconnect the alarm connector (D type connector). Remove the LPA module by removing the four retaining screws, replace with a new LPA module and secure it with the screws. Connect the RF cables to the LPA input and output connectors. Reconnect the wires to the alarm board connector pins 9 and 10. Reconnect the DC supply connector and turn the mains switch on. Note: Tighten SMA connectors using only a dedicated SMA torque spanner. If SMA connectors are over-tightened, irreparable damage will occur. . Do not use adjustable pliers to loosen/tighten SMA connectors.Also take care not to drop or knock the module as this can damage (or misalign in the case of tuned passive modules) sensitive internal components. Always store the modules in an environmentally friendly location Test equipment should always be used to verify the performance of any new module fitted to the system before broadcasting in the public domain. 5.13 Module Transportation: To maintain the operation, performance and reliability of any module it must be stored and transported correctly. Any module not installed in a whole system must be kept in an anti-static bag or container. Any module sent back to AFL for investigation/repair must be so protected. Please contact AFL’s quality department before returning a module.
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 20 of 23 6 APPENDIXES 6.1 Glossary of Terms used in this document Repeater or Cell Enhancer A Radio Frequency amplifier which can simultaneously amplify and re-broadcast Mobile Station and Base Transceiver Station signals. Band Selective RepeaterA Cell Enhancer designed for operation on a range of channels within a specified frequency band. Channel Selective RepeaterA Cell Enhancer, designed for operation on specified channel(s) within a specified frequency band. Channel frequencies may be factory set or on-site programmable. AC Alternating CurrentAGC Automatic Gain Control BBU Battery Backup Unit BTS Base Transceiver Station CEMS Coverage Enhancement Management System C/NR Carrier-to-Noise RatioDAB Digital Audio Broadcasting DC Direct CurrentDownlink (D/L) RF signals RX from the BTS to the Master Site FO Fibre OpticGND GroundID Identification NumberLED Light Emitting Diode LCX Coaxial Leaky Feeder LNA Low Noise Amplifier LPA Low Power Amplifier MOU Master Optical Unit M/S Master SiteMS Mobile StationMTBF Mean Time Between Failures N/A Not ApplicableN/C No ConnectionOFR On Frequency Repeater OIP3 Output Third Order Intercept Point = RFout +(C/I)/2PA Power AmplifierRF Radio FrequencyRSA Receiver/Splitter AmplifierRX ReceiverS/N Serial NumberTTL Transistor-Transistor Logic, a common type of digital circuit. TX TransmitterUplink (U/L) RF signals transmitted from the MS to the BTS VSWR Voltage Standing Wave Ratio WDM Wave division multiplex
6.2 AFL RF Module Drawing Key Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 21 of 23
6.3 EC Declaration of Conformity In accordance with BS EN ISO/IEC 17050-1&-2:2004 Aerial Facilities Limited Aerial House Asheridge Road CheshamBuckinghamshire HP5 2QD United Kingdom DECLARES, UNDER OUR SOLE RESPONSIBILITY THAT THE FOLLOWING PRODUCT: PRODUCT PART NO[S] 60-166801PRODUCT DESCRIPTION Baltimore Transit radio repeaters IN ACCORDANCE WITH THE FOLLOWING DIRECTIVES: 1999/5/EC The Radio & Telecommunications Terminal Equipment Directive Annex V and its amending directivesHAS BEEN DESIGNED AND MANUFACTURED TO THE FOLLOWING STANDARD[S] OR OTHERNORMATIVE DOCUMENT[S]: BS EN 60950 Information technology equipment. Safety. General requirementsETS EN 301 489-1 EMC standard for radio equipment and services.Part 1. Common technical requirements I hereby declare that the equipment named above has been designed to comply with the relevant sections of the above referenced specifications. The unit complies with all essential requirements of the Directives. SIGNEDB S BARTON TECHNICAL DIRECTOR DATE: 16/02/2006Registered Office: Aerial House, Asheridge Road, Chesham, Buckinghamshire, HP5 2QD England Registered No. 4042808 (England) www.aerialfacilities.comMaintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 22 of 23
Maintenance Handbook Baltimore Radio Repeater System Handbook No. 60-166801HBKM Page 23 of 23 6.4 Amendment List Record Sheet IssueNo.Date Incorporatedby Page Nos. AmendedReason for new issue A 09/02/2006 CMH 1st Draft 1 CMH 1st Issue Document Ref:- 60-166801HBKM

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