User Manual
Table Of Contents
- AMENDMENT LIST RECORD SHEET
- INTRODUCTION
- 1.SAFETY CONSIDERATIONS
- 2.OVERVIEW/SYSTEM DESCRIPTION
- 3.SPECIFICATION
- 4.SYSTEM DRAWINGS
- 5.SUB-UNIT MODULES
- 5.1VTA Downlink Duplexer Shelf 60-025302 (4U chassis)
- 5.2VTA Downlink Amplifier Shelf (50-025303, 8U Chassis)
- 5.2.1UHF 3dB Splitter (05-002603)
- 5.2.2¼Watt 0- -30dB Switched Attenuator \(10-00
- 5.2.3Low Noise Amplifier (11-006102)
- 5.2.4Low Noise Amplifiers (11-007302 & 11-007402)
- 5.2.4.1Description
- 5.2.4.2Technical Specification, (11-007302)
- 5.2.4.3Technical Specification (11-007402)
- 5.2.4.4Drg. No. 11-007302, LNA Assembly With Alarm Relay
- 5.2.4.5Drg. No. 11-007370, LNA RF Circuit Diagram
- 5.2.4.6Drg. No. 11-007371, LNA DC Wiring Diagram
- 5.2.5.7Drg. No. 11-003971, LNA DC Circuit Diagram
- 5.2.63 Stage Amplifier Alarm Boards (12-002201)
- 5.2.7450MHz 20W Power Amplifier (12-004201)
- 5.2.8Single DC/DC Converter (13-001702)
- 5.2.924V Single Relay Board (80-008902)
- 5.2.1024V 410W Power Supply (96-300054)
- 5.3VTA Downlink Channel Shelf (50-025304)
- 5.4VTA Uplink Duplexer Shelf (50-025305, 4U Chassis)
- 5.5VTA Uplink Amplifier Shelf (50-025306, 8U Chassis)
- 5.5.120Watt Class A Power Amplifier (12-016301)
- 5.5.2Automatic Gain Control (17-001101, Det. & 17-001201, Atten.)
- 5.5.2.1Description
- 5.5.2.2Technical Specification
- 5.5.2.3Drg. No. 17-001101, ACG Detector Assembly
- 5.5.2.4Drg. No. 17-001171, AGC Detector Circuit Diagram
- 5.5.2.5Drg. No. 17-001171C, AGC Detector Parts List
- 5.5.2.6Drg. No. 17-001201, AGC Attenuator Assembly Drawing
- 5.5.2.7Drg. No. 17-001270, AGC Attenuator Circuit Diagram
- 5.5.2.8Drg. No. 17-001270C, AGC Attenuator Parts List
- 6.INSTALLATION
- 7.MAINTENANCE
- APPENDIX AINITIAL EQUIPMENT SET-UP CALCULATIONS
9 Way Channelised UHF Cell Enhancer
Maintenance Handbook
H/book Number:-50-025301HBKM
Issue No:-
1
Date:-04/07/2003
Page:-
64 of 69
7. MAINTENANCE
7.1 General Procedures
7.1.1 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 shelves or trays and all housed within a standard 19” rack type cabinet.
Transmissions from the main base stations are passed though the system (via air interface
antennas) 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 the mobile
radio equipment to the base station is referred to as the uplink.
The first 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 Cell Enhancer Management System,
if fitted), or locally with the front panel LED’s. The green LED on the front panels of
shelves containing active components should be illuminated, while the red alarm indicator
should be off.
If an Alarm is on, then that individual shelf must be individually tested against the original
test specification.
The individual amplifier units within the shelf have a green LED showing through a hole in
their piggy-back alarm board, which is illuminated if the unit is working correctly.
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.