Weehawken Tunnel Radio VHF Repeater System User/Maintenance Handbook For G.E Transport Systems AFL Works Order Nō.: Q112727 AFL product part Nō.’s: 55-154701 (VHF Simplex BDA) 55-154801 (VHF Duplex BDA) 80-230801 (VHF Crystal Splitter) 80-230901 (VHF D/L Combiner) 80-231001 (VHF U/L Crystal Splitter) 80-231101 (VHF U/L Combiner) 80-231301 (VHF/UHF Power Supply) Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
Table of Contents INTRODUCTION ............................................................................................................................................6 Scope .............................................................................................................................................................................. 6 Purpose ....................................................................................................................................................
5.3.4 VHF Uplink Crystal Splitter, Drg. Nō. 80-231091 ................................................................................... 39 5.3.5 VHF Uplink Crystal Splitter Parts List...................................................................................................... 40 5.4 VHF Uplink Combiner (80-231101) ................................................................................................................. 41 5.4.1 VHF Uplink Combiner Description ..............................
7.12 Channel Selective Modules (17-009143 & 17-009127) ................................................................................ 64 7.12.1 Description ............................................................................................................................................ 64 7.12.2 Drg. Nō. 17-003080, Generic Channel Module Block Diagram ........................................................... 65 7.13 12 & 24V Relay Boards (20-001601 & 20-001602) ................................
AMENDMENT LIST RECORD SHEET Issue Nō. A Date 05/09/2005 Incorporated by CMH Page No.’s Amended Reason for new issue 1st Draft Document Ref:-Weehawken_VHF Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
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. Purpose The purpose of this handbook is to provide the user/maintainer with sufficient information to service and repair the equipment to the level agreed.
EC DECLARATION OF CONFORMITY In accordance with BS EN ISO/IEC 17050-1&-2:2004 0086 AERIAL FACILITIES LTD Aerial House Asheridge Road Chesham Bucks HP5 2QD United Kingdom DECLARES, UNDER OUR SOLE RESPONSIBILITY THAT THE FOLLOWING PRODUCT PRODUCT PART NO[S] 55-154701, 55-154801 PRODUCT DESCRIPTION Weehawken VHF amplifier system IN ACCORDANCE WITH THE FOLLOWING DIRECTIVES: 1999/5/EC directives The Radio & Telecommunications Terminal Equipment Directive Annex V and its amending HAS BEEN DESIGNED AND MANUF
Glossary of Terms Repeater or Cell Enhancer Band Selective Repeater Channel Selective Repeater AC AGC BBU BTS CEMS C/NR DC Downlink (D/L) FO GND ID LED LNA LPA MOU M.S. MTBF N/A N/C OFR OIP3 PA RF RSA Rx S/N Tx Uplink (U/L) VSWR WDM 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.
Key to AFL RF Module Drawing Symbols Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
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.
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.
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).
2. OVERVIEW/ SYSTEM DESCRIPTION 2.1 General System Description The Weehawken tunnel radio system is designed to amplify various bands of radio frequencies, in either channelised or band selective modes. This handbook is dedicated to the VHF radio repeating system. All the hardware (except the River Portal remote BDA) is built into standard 19” rack mounted cabinets which have an environmental IP rating of 54.
3. VHF REPEATER SYSTEM 3.1 VHF System Diagram, Drg. Nō. 80-231481 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
3.2 VHF Rack Layout and Downlink Interconnections Diagram, Drg. Nō. 80-231451 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
3.3 VHF Rack Layout and Uplink Interconnections Diagram, Drg. Nō. 80-231452 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
24V Inputs Handbook Nō.
3.5 Weehawken VHF System Frequencies Look-up Table Agency Jersey City Medical Center - EMS North Hudson Regional Fire and Rescue NJ Statewide Police (SPEN) Jersey City Medical Center - EMS Jersey City Medical Center - EMS North Hudson Regional Fire and Rescue Weehawken Township Weehawken Township New Jersey Transit Police Dept. Channel Number VHF CHN 1 VHF CHN 2 VHF CHN 3 VHF CHN 4 VHF CHN 5 VHF CHN 6 VHF CHN 7 VHF CHN 8 VHF CHN 9 Uplink Tx Downlink Rx 153.7850 154.3250 154.6800 155.2350 155.2800 158.
4. BAND SELECTIVE VHF CELL ENHANCERS 4.1 VHF Simplex BDA (55-154701) 4.1.1 VHF Simplex BDA Description The simplex shelves are part of the VHF amplification and have crystal filters instead of bandpass filters to set bandwidths. There are two downlink bands and three uplink bands, the downlink paths having isolators fitted to each of the 5Watt output stages to prevent two outputs from interfering with each other.
4.1.3 VHF Simplex BDA Mechanical Specification PARAMETER Height: Rack Width: Depth: Height: Shelves: Width: Depth: Temperature range: operational: storage: Weight: Humidity: RF Connectors: Environmental Protection: Case: Heatsinks: Finish: Handles: Fascia Supply Cable: SPECIFICATION Standard Eurorack 19" (482.6mm) 600mm (800 optional) 3U 19" (482.
4.1.4 VHF Simplex BDA System Diagram Drg. Nō. 55-154781 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
4.1.5 VHF Simplex BDA Shelf Outline Diagram Drg. Nō. 55-154791 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
4.1.6 VHF Simplex BDA Shelf Assembly (55-154701) Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002213 12-002220 12-002826 12-004902 13-001803 17-009143 17-009724 19-000826 19-000921 19-000924 20-001602 80-063920 91-030002 91-500001 91-510003 91-600001 91-600014 91-620001 91-700017 93-540035 96-110001 96-600002 96-600003 96-700017 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
4.2 VHF Duplex BDA (55-154801) 4.2.1 VHF Duplex BDA Description The duplex shelves are part of the VHF amplification and like the simplex shelves, have crystal filters instead of bandpass filters to set bandwidths. There are two downlink bands and three uplink bands, the downlink paths having isolators fitted to each of the 5Watt output stages to prevent reflections from interfering with the other channel.
4.2.3 VHF Duplex BDA Mechanical Specification PARAMETER Height: Rack Width: Depth: Height: Shelves: Width: Depth: Temperature range: operational: storage: Weight: Humidity: RF Connectors: Environmental protection: Case: Heatsinks: Finish: Handles: Fascia: Supply Cable: SPECIFICATION Standard Eurorack 19" (482.6mm) 600mm (800 optional) 3U 19" (482.
4.2.4 VHF Duplex BDA System Diagram 55-154801 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
4.2.5 VHF Duplex Shelf Outline Drawing, Drg. Nō. 55-154891 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
4.2.6 VHF Duplex BDA Shelf Assembly (55-154801) Parts List AFL Part Nō. 08-930002 10-000901 11-006002 12-002201 12-002213 12-002220 12-002826 12-004902 13-001803 17-001105 17-001107 17-009143 17-009725 19-000826 19-000921 19-000924 20-001601 80-008902 80-063920 91-030002 91-500001 91-510003 91-600001 91-600007 91-600014 91-620001 91-700017 96-110001 96-600002 96-600003 96-700034 96-700035 97-400005 Part Description 2 PORT ISOLATOR 150-300MHz SMA SW. ATTENUATOR 0.
5. VHF SPLITTERS/COMBINERS 5.1 5.1.1 VHF Downlink Crystal Splitter (80-230801) VHF Downlink Crystal Splitter Description The crystal splitter shelf is used in the downlink path to isolate the VHF channel frequencies at the inputs to the cell enhancers which amplify them.
5.1.3 VHF Downlink Crystal Filter System Diagram, Drg. Nō 80-230881 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.1.4 VHF Downlink Crystal Filter Shelf Outline Drawing, Drg. Nō. 80-230891 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.1.5 VHF Downlink Crystal Filter Shelf Parts List AFL Part Nō. 01-003105 05-002901 19-000921K 91-030002 91-130001 93-980124 93-980125 93-980126 93-980127 93-980128 93-980129 93-980131 93-980132 93-980133 Part Description SD NOTCH FILT.N 6 SECT.VHF H/B SMA 3dB BROADBAND SPLITTER SMA 1WATT 3U CHASSIS KIT (400mm deep) N ADAPTOR PANEL FEMALE:FEMALE SMA ADAPT 'T' ALL FEMALE 3 GHz 160.830MHz CRYSTAL FILT FAN4M52500 153.785MHz CRYSTAL FILT FAN4M52500 154.325MHz CRYSTAL FILT FAN4M52500 154.
5.2 5.2.1 VHF Downlink Combiner (80-230901) VHF Downlink Combiner Description The VHF downlink combiner shelf is the interface between the downlink VHF cell enhancers and the tunnel leaky feeder outputs. It consists of a number of two-to-one hybrid couplers which combine the outputs to two bandpass filters which only allow the specified VHF band to pass. Being a passive shelf, no alarms are present. 5.2.
5.2.3 VHF Downlink Combiner System Diagram, Drg. Nō. 80-230981 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.2.4 VHF Downlink Combiner Shelf Outline Drawing, Drg. Nō. 80-230991 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.2.5 VHF Downlink Combiner Parts List AFL Part Nō. 01-003105 19-000921K 91-030002 91-130001 05-000103 Part Description SD NOTCH FILT.N 6 SECT.VHF H/B SMA 3U CHASSIS KIT (400mm deep) N ADAPTOR PANEL FEMALE:FEMALE SMA ADAPT 'T' ALL FEMALE 3 GHz TX HYBRID COUPLER 3 PORT NO HTSINK Qty. 2 1 10 1 7 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.3 5.3.1 VHF Uplink Crystal Splitter (80-231001) VHF Uplink Crystal Splitter Description The uplink VHF crystal splitter shelf is the complement to the downlink crystal combiner shelf and uses the uplink frequency bands instead of the downlink bands. Being a passive shelf, no alarms are present. 5.3.
5.3.3 VHF Uplink Crystal Splitter System Diagram, Drg. Nō. 80-231081 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.3.4 VHF Uplink Crystal Splitter, Drg. Nō. 80-231091 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.3.5 VHF Uplink Crystal Splitter Parts List AFL Part Nō. 01-002503 01-003105 05-002901 19-000921K 91-030002 91-130001 93-980123 93-980125 93-980126 93-980127 93-980128 93-980129 93-980130 93-980131 93-980132 Part Description FILTER VHF H/B 6 SMA S 100W SD NOTCH FILT.N 6 SECT.VHF H/B SMA 3dB BROADBAND SPLITTER SMA 1WATT 3U CHASSIS KIT (400mm deep) N ADAPTOR PANEL FEMALE:FEMALE SMA ADAPT 'T' ALL FEMALE 3 GHz 161.520MHz CRYSTAL FILT FAN4M52500 153.785MHz CRYSTAL FILT FAN4M52500 154.
5.4 5.4.1 VHF Uplink Combiner (80-231101) VHF Uplink Combiner Description This shelf is the interface between the uplink VHF cell enhancers and the Tx antenna output port. The outputs of all the cell enhancers are first combined by combinations of two-to- one hybrid combiners which feed a triplexer filter array, which in turn, couple these three signals to the Tx antenna output port. This being a passive shelf, no alarms are present. 5.4.
5.4.3 VHF Uplink Combiner System Diagram, Drg. Nō. 80-231181 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.4.4 VHF Uplink Combiner Shelf Outline Drawing, Drg. Nō. 80-231191 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
5.4.5 VHF Uplink Combiner Parts List AFL Part Nō. 01-002503 01-003105 19-000921K 91-130001 91-030002 05-000103 Part Description FILTER VHF H/B 6 SMA S 100W SD NOTCH FILT.N 6 SECT.VHF H/B SMA 3U CHASSIS KIT (400mm deep) SMA ADAPT 'T' ALL FEMALE 3 GHz N ADAPTOR PANEL FEMALE:FEMALE TX HYBRID COUPLER 3 PORT NO HTSINK Qty. 2 1 1 2 10 6 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
6. POWER SUPPLIES & ALARMS 6.1 UHF/VHF Power Supply (80-231301) 6.1.1 UHF/VHF Power Supply Description The power supply shelves are separate for the VHF/UHF and 800MHz cell enhancers. The VHF/UHF supply shelf is a 24V DC shelf which supplies six, 24Volt XLR connector outputs at a maximum total output power of 800Watts DC. These DC outputs are fused at a 10Amp rating although four of the six DC outputs will be drawing less than 5Amps at any one time. 6.1.
6.1.4 UHF/VHF Power Supply Outline Drawing, Drg. Nō. 80-231391 Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
6.1.5 UHF/VHF Power Supply Parts List AFL Part Nō.
6.2 6.2.1 Alarm/Monitor Shelf (80-231303) Alarm/Monitor Shelf Description The alarm shelf acts as an alarm concentrator for all the alarms in the system. Firstly, within each shelf containing active components, the individually alarmed modules are ‘summed’ and presented to that shelves’ 9-way alarm connector as a volt-free relay contact pair. These alarm contact pairs are wired to the krone block in the lower rack space and from there the pairs are presented to the alarm shelf.
6.2.3 Alarm/Monitor Shelf Parts List AFL Part Nō. 19-000724 19-000725 19-000826 20-001601 91-520003 91-520005 91-520010 91-600014 91-600015 96-300072 96-600001 96-700034 96-700035 Part Description 1U 19" UNIT FRONT PANEL FAB 1U 19" UNIT 400 DEEP CHASSIS + BKT 2U,3U,4U 19" UNIT 400 DEEP LID 12V RELAY BOARD POWER SWITCHD/FUSED MAINS INL.
7. SUB-UNIT MODULES Note that the sub unit modules are tabled in part number order – the modules pertinent to any particular shelf will be found in the parts list under the heading of that shelf. 7.1 7.1.1 VHF High Band Bandpass + Notch Filter (01-003105) 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.
7.2 Tx Hybrid Coupler (05-000101) 7.2.1 Description The Hybrid 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. 7.2.
7.3 7.3.1 3 Port Tx Hybrid Coupler (05-000103) Description The transmitter hybrid couplers provide isolation from unwanted reflected frequencies to/from the leaky feeder antennas. They are 4 port devices with the one unused port terminated internally with a 50 Ω dummy load. Being passive devices, the hybrid couplers should be maintenance free over their entire lifetime and have an extremely high MTBF figure.
7.4 7.4.1 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. 7.4.
7.5 7.5.1 2-Port RF Isolator (08-930002) 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.
7.7 7.7.1 3 Stage Amplifier Alarm Board (12-002201) 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 1.20V across the collector current setting resistor.
7.7.2 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.
7.8 7.8.1 3 Stage Alarm/Simplex/Mute PCB (12-002213) 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. 7.9 7.9.
7.10 Dual DC/DC Converter (13-001803) 7.10.1 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.
7.11 D.I.P Channel Control Module (17-002101) 7.11.1 Description The operating frequency for each channel in each repeater is programmed by 16 DIL (Dual In Line) switches. The programming switches are mounted in the Channel Control Module. The Channel Selectivity Modules are connected to the Channel Control Module via multiway ribbon cables. Adjacent to the DIL switches for each channel is a toggle switch to turn on and off individual channels as required.
7.11.2 Programming Procedure Check that the required frequency falls within the operational frequency limits of the Cell Enhancer. For each channel required, subtract the synthesiser offset from the required operating frequency and record the resulting local oscillator frequency. Divide each local oscillator frequency by the channel spacing and check that the result is an integer (i.e: no remainder).
7.11.4 25kHz step size switch functions Switch Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Synthesiser offset added when switch in UP position +25kHz +50kHz +100kHz +200kHz +400kHz +800kHz +1.6MHz +3.2MHz +6.4MHz +12.8MHz +25.6MHz +51.2MHz +102.4MHz +204.8MHz +409.6MHz +819.2MHz 7.11.5 Programming Example Frequency required: 454.000MHz Channel spacing: 12.5kHz Synthesiser offset: -21.4MHz The Local Oscillator frequency is therefore: 454.000 – 21.4 = 432.
7.11.6 17-002101 Controller Module DIP Switch Connector Data IDC PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 25-way Connector 13 25 12 24 11 23 10 22 9 21 8 20 7 19 6 18 5 17 4 16 3 15 2 14 1 --- Function (12.5kHz steps) Freq. bit 1 (12.5kHz) Freq. bit 2 (25kHz) Freq. bit 3 (50kHz) Freq. bit 4 (100kHz) Freq. bit 5 (200kHz) Freq. bit 6 (400kHz) Freq. bit 7 (800kHz) Freq. bit 8 (1.6MHz) Freq. bit 9 (3.2MHz) Freq. bit 10 (6.4MHz) Freq. bit 11 (12.8MHz) Freq. bit 12 (25.
7.11.7 Drg. Nō. 17-002190, DIP Switch Module Controller Outline Drawing 1 ON CHANNEL 1 3 4 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 ON. 7 8 ON. 8 ON. 8 8 1 1 1 1 2 3 2 3 2 3 2 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 4 1 POW ER 16 SWITCH 1 ON. 8 SWITCH 16 ON. 8 5 ON CHANNEL 4 CHANNEL CONTROL MODULE THIRD ANGLE PROJECTION OFF 8 5 Tel : 01494 777000 Fax : 01494 777002 Aerial Facilities Limited England ON.
7.12 Channel Selective Modules (17-009143 & 17-009127) 7.12.1 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.
7.12.2 Drg. Nō. 17-003080, Generic Channel Module Block Diagram Weehawken Tunnel VHF Repeater System User/Maintenance Handbook Handbook Nō.
7.13 12 & 24V Relay Boards (20-001601 & 20-001602) 7.13.1 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.
7.14 12 & 24V Single Relay Board (80-008901 & 80-008902) 7.14.1 Description The General Purpose Relay Board allows the inversion of signals and the isolation of circuits. It is equipped with a single dual pole change-over relay RL1, with completely isolated wiring, accessed via a 15 way in-line connector.
8. INSTALLATION 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. 8.1 General Remarks The size and weight of the equipment racks mean that they represent a significant topple hazard unless they are securely bolted to the floor though the mounting holes in the base of the unit.
8.2 RF Connections All RF connections are made to the cable termination, located on the bulkhead at the rear of the equipment at floor level. 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. Ensure that connections are kept clean and are fully tightened. 8.
9. MAINTENANCE 9.1 9.1.1 Fault Finding 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 tunnel 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.
9.1.3 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.
9.1.6 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 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.
9.3 Care of Modules 9.3.1 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. 9.3.
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.
APPENDIX A INITIAL EQUIPMENT SET-UP CALCULATIONS GENERAL INFORMATION Client Name: AFL Equip. Model Nō. Site Name: Date: Model ANTENNA SYSTEMS Gain Azimuth Comments A - Service Antenna B – Donor Antenna Type Loss Length Comments 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.
