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:-
20 of 69
5.2 VTA Downlink Amplifier Shelf (50-025303, 8U Chassis)
5.2.1 UHF 3dB Splitter (05-002603)
5.2.1.1 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.
5.2.1.2 Technical Specification
PARAMETER SPECIFICATION
Frequency Range:
400-500 MHz
Power Rating: 5 Watts
Insertion Loss: 5.2dB Typical
VSWR: 1.2:1
Impedance: 50 Ohms
Connectors: SMA
Weight: <0.5Kgs
Mechanical: Drawing No. 07-003890
5.2.2 ¼Watt 0- -30dB Switched Attenuator (10-000701)
5.2.2.1 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.
5.2.2.2 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. The attenuation is simply set using the four
miniature toggle switches on the top of each unit. Each switch is clearly marked with the
attenuation it provides, and the total attenuation in line is the sum of the values switched
in. They are designed to maintain an accurate 50 impedance over their operating
frequency at both input and output.