W4UVV
Member
FYI The Prince George Co. Board of Supervisors (BOS) previously listed bid for a consultant to aid in the replacement of the county's present UHF analog repeater system has resulted with AECOM, Lynchburg? selected for the $175,000 (no typo) contract. Each county radio user representatives i.e., Police, Sheriff, VFD, EMS, School Board and Utilities had a separate one day interview with the consultant last week.
Following are my observations and opinions: In my and a number of area ham's, scanner monitor's and former county employees opinion's, the current county's radio system performance results reflect, in part, previously technical decisions made by non-technical management. As an example, per a retired PG dispatcher/current VFD member, the EMS repeater has had such poor coverage, often county ambulances had to use a cellphone to communicate with the county dispatcher when at MCV, Richmond.
Could possibly the partial grove of trees relatively close by on the north side of the Courthouse tower at the same height or higher (T@92 ft. & R@83 ft.) be absorbing some of the omni-directional RF? I believe so.
The seven existing "new" county tower structures transmit/receive heights with six repeaters are:
1. Courthouse T@92 ft. R@83 ft.
2. Burrowsville T@90 ft. R@60 ft.
3. Garysville T@110 ft. R@85 ft.
4. Disputanta T@127ft. R@111 ft.
5. Tavern Road T@97 ft. R@89 ft.
6. Carson T@86 ft. R@84 ft.
7. Middle Road (non-repeater site) T@ 85 ft. R@85 ft.
The tower transmit/receive heights listed are relatively close to the actual tower heights themselves.
All seven tower sites use 6000 mhz. PTP MW links T/R comm links. Middle Road/Courthouse EOC T/R comms are via 15, 20 and 21 Ghz. PTP MW links.
The tower transmit/receive heights listed are relatively close to the actual tower heights themselves.
As a comparison two air miles west from the Courthouse area, my ground elevation is 145 ft. above sea level level. My comm tower with a 21ft. schedule 80 aluminum section mast pipe extension inserted at the topping section load relief bearing/rotor interface is about 115 ft. at its' highest point. At the very top is my Diamond dual band 2 meter/440 mhz. ground plane antenna with various RF pre-amped scanner antennas mounted lower. No self respecting ham or scanner monitor I know ever would have given up an on site 190 ft. lattice tower antenna platform in good condition already installed adjacent to the Police Station Dispatch/Courthouse for a new 92 ft. tower constructed approximately 175 ft away relatively close trees to its' north side.
That begs more questions, for example, one of which is, if the present Courthouse tower ground elevation is about 130 ft. above sea level with the 453 mhz. analog omni-directional repeaters having coverage area issues and four of the six repeater site towers are under 100 ft in height, what will the coverage be on 800 mhz.? Odds are it will be as bad or worse. The towers are what were installed and are not lattice types. I doubt they can be extended in height.
The previous Courthouse vhf lattice type tower, which supported police, fire and ems on 155.1150 and 155.5500 mhz. repeaters was 190 ft. high with a maximum allowed height up to 199 ft. Maybe, in part, that's why I could receive PG county vhf comms mobile south to the NC line and on occasions as far northeast in Maryland to near Andrews AFB base. Area reception mobile was never a problem I experienced. Unfortunately, the county sold that tower, which still was in good condition and paid for years ago. Also, the county relinquished back to the FCC its' vhf high band frequencies, a few of which were scooped up quickly by Dinwiddie Co. for its' P25 digital comms.
Possibly in 2017 a replacement 800 mhz. digital trunked radio system P1 and P2 will be recommended by the consultant. Depending upon what trs is recommended, the BOS will vote either to approve or disapprove and request a revised partial resubmission be made. I hope history does not repeat from the previous "new" replacement county radio system process and previous technically competent voices this time will be solicited and listened to instead of ignored. Those voices should include, but are not limited to the current operator of the Prince George Co. 444.2750 mhz. Disaster comms repeater and other RF technical competent knowledgeable individuals such as the County Emergency Coordinator, etc. others.
Time will tell one way or the other. As I receive updates of interest I will post them to this thread.
John
W4UVV
Following are my observations and opinions: In my and a number of area ham's, scanner monitor's and former county employees opinion's, the current county's radio system performance results reflect, in part, previously technical decisions made by non-technical management. As an example, per a retired PG dispatcher/current VFD member, the EMS repeater has had such poor coverage, often county ambulances had to use a cellphone to communicate with the county dispatcher when at MCV, Richmond.
Could possibly the partial grove of trees relatively close by on the north side of the Courthouse tower at the same height or higher (T@92 ft. & R@83 ft.) be absorbing some of the omni-directional RF? I believe so.
The seven existing "new" county tower structures transmit/receive heights with six repeaters are:
1. Courthouse T@92 ft. R@83 ft.
2. Burrowsville T@90 ft. R@60 ft.
3. Garysville T@110 ft. R@85 ft.
4. Disputanta T@127ft. R@111 ft.
5. Tavern Road T@97 ft. R@89 ft.
6. Carson T@86 ft. R@84 ft.
7. Middle Road (non-repeater site) T@ 85 ft. R@85 ft.
The tower transmit/receive heights listed are relatively close to the actual tower heights themselves.
All seven tower sites use 6000 mhz. PTP MW links T/R comm links. Middle Road/Courthouse EOC T/R comms are via 15, 20 and 21 Ghz. PTP MW links.
The tower transmit/receive heights listed are relatively close to the actual tower heights themselves.
As a comparison two air miles west from the Courthouse area, my ground elevation is 145 ft. above sea level level. My comm tower with a 21ft. schedule 80 aluminum section mast pipe extension inserted at the topping section load relief bearing/rotor interface is about 115 ft. at its' highest point. At the very top is my Diamond dual band 2 meter/440 mhz. ground plane antenna with various RF pre-amped scanner antennas mounted lower. No self respecting ham or scanner monitor I know ever would have given up an on site 190 ft. lattice tower antenna platform in good condition already installed adjacent to the Police Station Dispatch/Courthouse for a new 92 ft. tower constructed approximately 175 ft away relatively close trees to its' north side.
That begs more questions, for example, one of which is, if the present Courthouse tower ground elevation is about 130 ft. above sea level with the 453 mhz. analog omni-directional repeaters having coverage area issues and four of the six repeater site towers are under 100 ft in height, what will the coverage be on 800 mhz.? Odds are it will be as bad or worse. The towers are what were installed and are not lattice types. I doubt they can be extended in height.
The previous Courthouse vhf lattice type tower, which supported police, fire and ems on 155.1150 and 155.5500 mhz. repeaters was 190 ft. high with a maximum allowed height up to 199 ft. Maybe, in part, that's why I could receive PG county vhf comms mobile south to the NC line and on occasions as far northeast in Maryland to near Andrews AFB base. Area reception mobile was never a problem I experienced. Unfortunately, the county sold that tower, which still was in good condition and paid for years ago. Also, the county relinquished back to the FCC its' vhf high band frequencies, a few of which were scooped up quickly by Dinwiddie Co. for its' P25 digital comms.
Possibly in 2017 a replacement 800 mhz. digital trunked radio system P1 and P2 will be recommended by the consultant. Depending upon what trs is recommended, the BOS will vote either to approve or disapprove and request a revised partial resubmission be made. I hope history does not repeat from the previous "new" replacement county radio system process and previous technically competent voices this time will be solicited and listened to instead of ignored. Those voices should include, but are not limited to the current operator of the Prince George Co. 444.2750 mhz. Disaster comms repeater and other RF technical competent knowledgeable individuals such as the County Emergency Coordinator, etc. others.
Time will tell one way or the other. As I receive updates of interest I will post them to this thread.
John
W4UVV