Tusa Consulting Services Ben Hill County, Georgia Board of Commissioners Testing and Analysis
Introduction #1 – Confirm radio programming #2 – Confirm licensing/ site ERP #3 – Confirm amplifier configuration #4 – Perform intermodulation/ co-location study #5 – Perform noise floor measurements #6 – Perform line sweeps
Task #1 - Radio Programming Confirmed correct programming of basestations Sheriff’s Hospital Volunteer Fire Road Department County Jail Confirmed correct programming of mobiles Focused on Sheriff’s Office Confirmed correct programming of portables
Task #2 – ERP / FCC Licensing Sheriff’s Office – Triangle Tower TX: 159.9000 RX: 154.9000 EMS – Hospital Tower TX: 155.2350 RX: 151.2650 Volunteer Fire – GA Forestry Tower TX: 155.7150 RX: 153.9500 Road Department TX: 158.8950 RX: 153.9050
Task #2 – ERP / FCC Licensing Sheriff’s Office – Triangle Tower TX: 159.9000 RX: 154.9000 Not licensed for 154.9000 Not an actual VHF frequency Should be one of these: 154.6650 154.9350 155.6250
Task #3 – Amplifier Configuration Confirmed Sheriff’s basestation and amplifier are operating within FCC licensed ERP.
Task #4 – Intermodulation Study Intermod interference is a process in which multiple transmitted frequencies combine to produce a result that impairs receive performance. Sources can be other local or distant towers, but typically created from within the same site as receive system. Not the same as co-location interference. More to come with Task #4….
Task #5 - Effective Sensitivity
Task #6 - Perform Line Sweeps ‘System’ sweeps performed at each site Return Loss, Distance to Fault No issues found at any site
Task #4 – Co-Location Study EMS Receive Frequency – 151.2650 MHz
Task #4 – Co-Location Study Vol. Fire Receive Frequency – 153.9500 MHz
Task #4 – Co-Location Study Road Dept. Receive Frequency – 153.9050 MHz
Task #4 – Co-Location Study Sheriff’s Receive Frequency – 154.9000 MHz Statewide TX Frequency – 154.9050 MHz
Task #4 – Co-Location Study Statewide Use of – 154.9050 MHz
Conclusion Sheriff needs to reprogram all radios to different currently licensed receive frequency: 154.6650 154.9350 155.6250 Relocate all agencies to centrally located tower with more height Conservation of resources Single improved site Vs. multiple/scattered/inadequate Single point of contact/ responsibility for preventative and corrective radio maintenance and system organization
Project Conclusion Testing and Analysis Report
Questions?