2 Channel VHF Repeater User Handbook For W.O.W AFL Works Order Nō.:Q112547 AFL product part Nō.:50-122501 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
Table of Contents AMENDMENT LIST RECORD SHEET ...................................................................................................4 INTRODUCTION.........................................................................................................................................5 Scope ........................................................................................................................................................................... 5 Purpose ..........................
4.9.2 Technical Specification............................................................................................................................. 29 4.10 Six-Way Splitter (93-100004)..................................................................................................................... 30 4.10.1 Description ........................................................................................................................................... 30 4.10.2 Technical Specification........
AMENDMENT LIST RECORD SHEET Issue Nō. A Date 29/03/05 Incorporated by CMH 1 Page No.’s Amended Reason for new issue 1st Draft 1st Issue CMH Document Ref:-50-122501HBK 12 Channel Channelised Cell Enhancer User 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 AFL recommends that the installer of this equipment familiarise his/herself with the safety and installation procedures contained within this document before installation commences.
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.
Key to AFL RF Module Drawing Symbols 12 Channel Channelised Cell Enhancer User 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 The AFL Channel Selective Cell Enhancer is a 2-way on-band repeater. Various models are available to cover frequency bands from 50MHz to 3000MHz. Its main 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 and tunnels, etc.
3. SPECIFICATION 3.P Cell Enhancer Case Internal Photograph 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
3.1 Description The system consists of separate modules mounted within a lockable, environmentally protected enclosure. It is designed to amplify twelve bi-directional channels (six uplink, six downlink) of mobile signals operating in the VHF waveband. All twelve channel selective modules are configurable for any frequency (within the channel modules’ designed range) set by the DIP switches on the channel control modules – see section 4.8 for channel frequency calculation examples.
3.
3.4 System Diagram, Drg. Nō. 50-122580 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
3.5 Generic System Case Outline Drawing 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
3.5 Parts List AFL Part Nō.
4. SUB-UNIT MODULES 4.1 4.1.1 3 Port Tx Hybrid Couplers (05-000103 & 05-000104) 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. The ‘104’ version has higher power capability due to an attached heatsink.
4.2 4.2.1 ¼Watt 0- -30dB Switched Attenuator (10-000703) 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. 4.2.2 Switched Attenuators The AFL switched attenuators are available in two different types; 0 – 30dB in 2 dB steps (as in this case), or 0 – 15dB in 1 dB steps.
4.3 4.3.1 VHF/UHF Low Noise Amplifier (11-006002) Description The 21dB gain low noise amplifier used is a double stage solid-state low-noise amplifier. Class A circuitry is used throughout the unit to ensure excellent linearity over a very wide dynamic range. The two active devices are very moderately rated to provide a long, troublefree working life. There are no adjustments on this amplifier, and in the unlikely event of failure then the entire amplifier should be replaced.
4.4 4.4.1 10Watt Power Amplifier (12-002001) Description The power amplifier fitted to this unit is a multi-stage, solid state power amplifier. Class A circuitry is employed throughout the device to ensure excellent linearity over a wide dynamic frequency range. All the semi-conductor devices are very conservatively rated to ensure low device junction temperatures and a long, trouble free working lifetime. The power amplifier should require no maintenance over its operating life.
4.5 20Watt Power Amplifier (12-003601) 4.5.1 Description The 20Watt power amplifier fitted to this unit is a multi-stage, solid state power amplifier. Class A circuitry is employed throughout the device to ensure excellent linearity over a wide dynamic frequency range. All the semi-conductor devices are very conservatively rated to ensure low device junction temperatures and a long, trouble free working lifetime. The power amplifier should require no maintenance over its operating life.
4.6 4.6.1 DC/DC Converter, 24V in, 12V 8A out (13-003011) Description The DC/DC converter fitted is an O.E.M high power PCB unit with an 8 amp @ 12V output capability. The regulator exists within this unit because of the need to supply 12V DC to the channel modules; if the unit is being supplied with power by the external 24V DC rail, there would be only be 24V in the system and the channel modules would have no power. The circuit is basically an O.E.
4.7 4.7.1 Channel Control Module (17-002101) 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’. 4.7.2 Technical Specification Below shows the pin assignments for each switch on a channel control module.
4.7.3 VHF/ UHF 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).
4.7.4 VHF/ UHF Programming Example Frequency required: 465.5MHz Channel spacing: 12.5kHz Synthesiser offset: 21.4MHz The Local Oscillator frequency is therefore: 465.4 – 21.4 Dividing the LO frequency by the channel spacing of: = 444.0 MHz 0.0125MHz: 444.0 = 35520 0.0125 This is an integer value, therefore it is OK to proceed. Local Oscillator Frequency of: 444.
4.8 4.8.1 Channel Selective Module (17-009106) 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.
4.8.2 Drg. Nō. 17-003080, Generic Channel Module Block Diagram 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
4.9 24V Relay Board (20-001602) 4.9.1 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.
4.10 Six-Way Splitter (93-100004) 4.10.1 Description The wide range, low power, hybrid splitter/combiner provides the means to divide the signal into six before the channel modules & re-combine the six signals into one after processing. Being passive devices, the receivers should be maintenance free over their entire lifetime and have an extremely high MTBF figure.
4.12 JWS100-12/A PSU (96-300051) 4.12.1 Description The mains power supply unit used to power the channel selective modules is a switchedmode type capable of supplying 12V DC at 8.5Amps continuously, (the cell enhancer draws approximately 5.0Amps from this 12V supply under normal conditions). No routine maintenance of the PSU is required. If a fault is suspected, then the output voltage from the power supply may be measured on its output terminals. This is typically set to 12.2V.
4.13 24V, 400W Power Supply Pack (96-300054) 4.13.1 Description The main 24V power supply unit is a switched-mode type capable of supplying 24V DC at 17.0Amps continuously. Equipment of this type typically requires approximately 12.0 Amps at 24V DC, so the PSU will be used conservatively ensuring a long operational lifetime. No routine maintenance of the PSU is required. If a fault is suspected, then the output voltage from the power supply may be measured on its output terminals.
5. INSTALLATION 5.1 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. 5.
5.3 A). Antenna Isolation First set up the two antennas & measure the isolation between them. Yagi Yagi or leaky feeder Measure Isolation Between antennas Mobiles Base Site B) Install the Cell Enhancer with its gain set 10dB below the isolation figure obtained above. Yagi Yagi or leaky feeder Base Port Mobile Port Cell Enhancer Base Site (donor) Mobile 12 Channel Channelised Cell Enhancer User Handbook Handbook Nō.
6. MAINTENANCE 6.1 6.1.1 General Procedures 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 within a wall mounted, environmentally protected 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.
6.1.2 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.
6.1.5 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. 6.1.6 Service Support Advice and assistance with maintaining and servicing this system are available by contacting Aerial Facilities Ltd. 6.
6.3 6.3.1 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. 6.3.
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 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 dBm dB dBm V DOWNLINK CALCULATIONS Parameter Comments Input signal level (G) CE max.
