Table of Contents
1. Antenna Specifications and Installation Criteria...........................................................................8
1.1. Base (Donor) Input...................................................................................................................8
1.1.1. Required Input Information...............................................................................................8
1.2. Service Antenna Requirements ...............................................................................................9
1.2.1. Required Radiating Antenna Information..........................................................................9
1.3. RF Cabling Requirements........................................................................................................9
2. Pre-Installation Requirements....................................................................................................10
2.1. Safety Guidelines...................................................................................................................10
2.2. Selecting a Location...............................................................................................................10
2.2.1. Cooling and Airflow.........................................................................................................10
2.2.2. Wall Compatibility...........................................................................................................10
2.2.3. Access to the Line Amplifier ...........................................................................................10
3. WMATA Dual Band UHF Line Amplifier 55-227901...................................................................11
3.1. Equipment Overview..............................................................................................................11
3.2. Theory of operation................................................................................................................11
3.3. System Diagram ....................................................................................................................12
3.4. Table of Components by Position Number ............................................................................13
3.5. Exploded schematic showing Downlink RF path and components........................................14
3.6. Exploded schematic showing Uplink RF path and components ............................................15
3.7. Front View..............................................................................................................................16
3.8. Side Views.............................................................................................................................17
3.9. Interior Picture - Downlink Path .............................................................................................18
3.10. Interior Picture - Uplink Path..................................................................................................19
3.11. Specification...........................................................................................................................20
4. Installation –General Notes.......................................................................................................21
4.1. General Remarks...................................................................................................................21
4.2. Electrical Connections ...........................................................................................................21
4.3. RF Connections.....................................................................................................................21
4.3.1. Termination of Unused Ports..........................................................................................21
4.4. Commissioning ......................................................................................................................22
4.5. RF Installation & Gain Calculations .......................................................................................22
5. Maintenance...............................................................................................................................23
5.1. Fault Finding..........................................................................................................................23
5.1.1. Quick Fault Checklist......................................................................................................23
5.1.2 Fault Isolation.....................................................................................................................23
5.1.3. Downlink.........................................................................................................................24
5.1.4. Uplink..............................................................................................................................24
5.1.5. Checking service ............................................................................................................24
5.1.6. Fault repair......................................................................................................................24
5.1.7. Service Support..............................................................................................................25
5.2. Tools & Test Equipment.........................................................................................................25
5.3. Care of Modules.....................................................................................................................26
5.3.1. General Comments.........................................................................................................26
5.3.2. LNA Replacement (general procedure)..........................................................................26
5.3.3. Module Replacement (general procedure).....................................................................26
5.3.4. Power Amplifier Replacement (general procedure)........................................................26
5.3.5. Low Power Amplifier Replacement (general procedure) ................................................27
5.3.6. Module Transportation:...................................................................................................27
Appendix A...........................................................................................................................................28
A.1. Glossary of Terms used in this document..............................................................................28
A.2. Key to Drawing Symbols used in this document....................................................................29
A.3. Document Amendment Record..............................................................................................30