Robbyboy
Cat Herder
Speaking about the coast, I have been monitoring VIPER for about 6 months now and while its few and far between (transmissions) I have logged traffic on three talkgroups for the Jacksonville Site.
2005-2008 VIPER Discussion (Archive)
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This thread has earned a sticky...once I get caught up here at work in a little while I will add some more Control Channel info I found on my trip to Central NC over the weekend...System sounds good in Wake County 
Marshall KE4ZNR
Marshall KE4ZNR
Ok, heading west from Wake County on I40 yesterday I found 2 control channels that showed the VIPER system ID of 6038:
868.6875Mhz--Shows up as WQBK492 Chapel Hill/Chatham County licensed for the VIPER system...
868.7125Mhz--Shows up as WPXZ639 Hillsborough/Orange County licensed for the
Viper system...
Neither of these 2 sites were exactly hopping with activity...I heard a little NCSHP traffic along with the TTA (Triangle Transit Authority) Talkgroup...
I was unable to map out the other site frequencies at each location ut at least we now have 2 more VIPER Control Channels figured out...
Marshall KE4ZNR
868.6875Mhz--Shows up as WQBK492 Chapel Hill/Chatham County licensed for the VIPER system...
868.7125Mhz--Shows up as WPXZ639 Hillsborough/Orange County licensed for the
Viper system...
Neither of these 2 sites were exactly hopping with activity...I heard a little NCSHP traffic along with the TTA (Triangle Transit Authority) Talkgroup...
I was unable to map out the other site frequencies at each location ut at least we now have 2 more VIPER Control Channels figured out...
Marshall KE4ZNR
The Chapel Hill site is Terrell's Mtn, also known as Chatham Mtn, is just inside Chatham County from Carrboro and is on the WUNC-TV tower. The Hillsborough site is Occoneechi Mtn, also known as Eno Mtn, and is the one highly visible from the eastern junction of I-40 and I-85 at Hillsborough.
New Hanover officials are taking a sensible approach to communications issues including VIPER interoperability.
How New Hanover County is dealing with its public safety communications situation:
http://islandgazette.net/newspm/localnews_more.php?id=3696_0_2_0_M45
Really something to see a newspaper go into so much detail on the subject.
How New Hanover County is dealing with its public safety communications situation:
http://islandgazette.net/newspm/localnews_more.php?id=3696_0_2_0_M45
Really something to see a newspaper go into so much detail on the subject.
To quote the story.........
If wx4cbh can work miricles with keeping moto equipment that has not been supported for this many years, NHC can stretch it out :lol:
Is this where PS radio systems are headed? New systems every 8 or 9 years?
When NHC put up that system, the reason was "this will last up years, we won't have to shell out a lot of money for a long time" I can almost see how some PS agencies are pushed to use nextel. Lost cost handsets instead of $1500-$4000 HTs.
OK, I know that was starting to veer OT.
If wx4cbh can work miricles with keeping moto equipment that has not been supported for this many years, NHC can stretch it out :lol:
Is this where PS radio systems are headed? New systems every 8 or 9 years?
When NHC put up that system, the reason was "this will last up years, we won't have to shell out a lot of money for a long time" I can almost see how some PS agencies are pushed to use nextel. Lost cost handsets instead of $1500-$4000 HTs.
OK, I know that was starting to veer OT.
And now some of the 70 mHz link equipment for the low band stuff in another troop is in trouble and is gonna have to be "rejuvenated" since the replacement system is obviously a coupla years away. Good thing we at Greensboro siezed the opportunity to scrounge up several 70 mHz Micor pieces from a surplus dealer a few months back 'cuz that means we got some we can share with other troops.
I have mapped the progress of VIPER so far this year.
License stipulated construction deadlines are mid-2006.
You can see the expansion phase in the east and another development along I-77.
Also, this only shows site location and doesn't represent actual signal coverage.
License stipulated construction deadlines are mid-2006.
You can see the expansion phase in the east and another development along I-77.
Also, this only shows site location and doesn't represent actual signal coverage.
You did not list Duplin County, Pender Countyand some other down east counites. It has had the TRS up for 2 or 3 years.
One aspect of VIPER that I am quite curious about is how well 800MHz will work in the mountains of western North Carolina.
The VIPER project people point to the success of the Colorado state 800MHz system.
That comparison seems questionable.
The Rocky Mountains and the Appalachians are a bit different to say the least.
Surprisingly though, I am not finding information suggesting that 800MHz would be total disaster.
The VIPER project people point to the success of the Colorado state 800MHz system.
That comparison seems questionable.
The Rocky Mountains and the Appalachians are a bit different to say the least.
Surprisingly though, I am not finding information suggesting that 800MHz would be total disaster.
One study I found relevant to 800MHz coverage in the mountains was done back in 1998 for the Department of Justice. Under the Public Safety Wireless Network program, 800MHz's suitablity for public safety usage was analyzed.
It was concluded that even though signal fading and losses due to terrain and foilage are greater at 800MHZ than VHF, the losses are insignificant. It is not until the GHz range that performance is noticeably affected. Coniferous trees with pine needles are more troublesome causing signal scatter at 800MHz.
Source:
800 MHz Study
Booz - Allen & Hamilton, Inc.
March 23, 1998
Prepared for PSWN Program Management Office
http://www.safecomprogram.gov/NR/rdonlyres/1EC47ABD-89BA-40F2-B55A-F83C4B4189A8/0/800MHz_study.pdf
It was concluded that even though signal fading and losses due to terrain and foilage are greater at 800MHZ than VHF, the losses are insignificant. It is not until the GHz range that performance is noticeably affected. Coniferous trees with pine needles are more troublesome causing signal scatter at 800MHz.
Source:
800 MHz Study
Booz - Allen & Hamilton, Inc.
March 23, 1998
Prepared for PSWN Program Management Office
http://www.safecomprogram.gov/NR/rdonlyres/1EC47ABD-89BA-40F2-B55A-F83C4B4189A8/0/800MHz_study.pdf
The needle length vs. wavelength match was explained in the study. Just like you point out.
It wouldn't only be a mountain phenomena. Lot of pine trees out east.
What kind of discussion has been generated on the subject?
Note: A couple new license pending sites have been added (in red) to the VIPER map attached a couple of posts back.
1811 CAMDEN AVENUE
DURHAM, NC DURHAM County
HERBERT FAUCETTE ROAD
BULLOCK, NC GRANVILLE County
HIGHLAND & BRIDGE STREET
ELKIN, NC SURRY County
It wouldn't only be a mountain phenomena. Lot of pine trees out east.
What kind of discussion has been generated on the subject?
Note: A couple new license pending sites have been added (in red) to the VIPER map attached a couple of posts back.
1811 CAMDEN AVENUE
DURHAM, NC DURHAM County
HERBERT FAUCETTE ROAD
BULLOCK, NC GRANVILLE County
HIGHLAND & BRIDGE STREET
ELKIN, NC SURRY County
The discussion centers around how eastern NC would have a real problem with 450 and 800 mHz radio due to the number of pine trees. So far the problems outlined in the discussions don't hold much water. RF engineers acknowledge the theory and work beyond it by specifying equipment that overcomes the shortcomings. Well OK, in most cases, at least. There are several cases where some bean counter or local politician(s) with ideals of saving money (they always know more than engineers) has managed to cut the budget to a point that inadequate coverage is the result. Those are the examples people point the finger at when saying UHF won't work where there are pine trees.
Antenna tweaking and satellite receiver sites are the norm for conventional base stations and repeaters of any band, but the higher you go in frequency, the more critical the relationship between these parameters becomes. Terrain and vegetation coupled with rural/low density structure versus urban/suburban high density structures and how effective you want the in-building coverage to be are the prime considerations. Antenna types (gain factor, downtilt, propagation patterns, etc), mounting location effects on patterns, height above average terrain, feedline losses, etc. determine how well the transmitters and receivers perform in a given application. Sometimes a top mounted RX preamp is required, and sometimes multiple receiver sites are required, and sometimes lots of height and plenty of downtilt gets the job done when nothing else does. 30+ years of experience has proved to me that rarely does the no downtilt/nosebleed height antenna combo give satisfactory results unless your objective is station-to-station coverage or mobiles only with little handheld use, but it still seems to be the norm.
And I've always wondered how the bean counter who cuts the microwave link system outta the multiple receiver site plans in favor of dedicated twisted pairs thinks that saves any money. You can usually pay for the MW within about 5 years of line leases. Oh well.
And I've always wondered how the bean counter who cuts the microwave link system outta the multiple receiver site plans in favor of dedicated twisted pairs thinks that saves any money. You can usually pay for the MW within about 5 years of line leases. Oh well.
Bottom line: any frequency range can be made to operate to expectation IF the engineering is valid and IF the proper equipment is chosen in sufficient quantities to do the job. Whether the state will be successful at any location or not depends on how much of the project is real engineering and how much is "sales engineering" and how much is bean counter engineering. If the state says those things, then they'll have to back it up with real engineering and sufficient funding. There are too many successful systems operating under extreme terrain conditions to say that 800 won't work in the mountains of NC.
Just an opinion, but if they continue to put up these colinear stick antennas with no down tilt, then they will continue to be disappointed in the performance at some locations.
And now for an example of sales engineering or of idiots at work. A city I know of was having a problem with fire department portable radios being able to talk anywhere within the obvious range of the radio system. The FDs question was why could the PD operate with portables only and they couldn't? The answers were perfectly obvious, even to those without a great deal of comm experience. Number 1, the PD had 8 satellite receiver sites to the FDs 3, and two are in lousy locations, and the portables had speaker microphones with antennas compared to the FDs standard speaker mics. If the antenna is on the portable and buried in the turnout gear and you have only 3 receiver sites, two of which are not in advantageous locations, you figure out why the things didn't work.
Now then, they hired a "consultant," and this so-called consultant made his recommendations and the city followed suit. Yes, they purchased new 250 watt transmitters and 9.5 db gain antennas to replace the 100 watters with the old crummy 6 db antennas. Anybody see anything wrong here? You could then copy the scratch of the portables feeble attempts from over 90 miles away instead of a mere 30 miles away. That's called "sales engineering."
Just an opinion, but if they continue to put up these colinear stick antennas with no down tilt, then they will continue to be disappointed in the performance at some locations.
And now for an example of sales engineering or of idiots at work. A city I know of was having a problem with fire department portable radios being able to talk anywhere within the obvious range of the radio system. The FDs question was why could the PD operate with portables only and they couldn't? The answers were perfectly obvious, even to those without a great deal of comm experience. Number 1, the PD had 8 satellite receiver sites to the FDs 3, and two are in lousy locations, and the portables had speaker microphones with antennas compared to the FDs standard speaker mics. If the antenna is on the portable and buried in the turnout gear and you have only 3 receiver sites, two of which are not in advantageous locations, you figure out why the things didn't work.
Now then, they hired a "consultant," and this so-called consultant made his recommendations and the city followed suit. Yes, they purchased new 250 watt transmitters and 9.5 db gain antennas to replace the 100 watters with the old crummy 6 db antennas. Anybody see anything wrong here? You could then copy the scratch of the portables feeble attempts from over 90 miles away instead of a mere 30 miles away. That's called "sales engineering."
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