Colo DTRS 800 Coverage - your opinion

[mikepdx]

Hello to the Colorado Forum.

I'm a native Oregonian and live in Oregon
now (but lived in Golden, CO for 8 years).

Not to intrude, but I had a question for all:

How are the signal levels on the new Colo State 800
system? I'm especially curious of the signal levels
(reception) in the mountainous areas, and if
you've heard any comments by users on the air about
the system coverage.

It's hard to shake what's been drilled into my head
all of my radio life, namely:
Lo-Band - Best for rural areas.
Hi-Band - Good for Rural and SemiUrban
UHF - Best for urban
800? for mountainous areas? Ain't gonna happen.

I've read two different comments about coverage
in documents I read at the state of Colo DTRS site that
seem to contradict each other:
-Expect around 20% less coverage than VHF-HI.
-Tests show 800 coverage better than the old VHF-HI system.

I ask for an un-biased point of view from you, the scanner
listeners, as opposed to a bureaucrat on the hunt for another
new radio grant. Your opinions, or reports you've heard from
DTRS users you know would be interesting. I'd love to know
what CSP thinks about the system. (I was a CSP <hi-band>
buff).

I read this forum with much interest, as our State has not
yet a statewide trunked system. I'm sure it's only a matter
of time, and they will undoubtedly buy the top technology.
It wont be 800 trunked analog, for sure.

thanks for the peek - I learn alot here.

Michael
Corbett, OR

 

[jimmnn]

Hello to the Colorado Forum.

I'm a native Oregonian and live in Oregon
now (but lived in Golden, CO for 8 years).

Not to intrude, but I had a question for all:

How are the signal levels on the new Colo State 800
system? I'm especially curious of the signal levels
(reception) in the mountainous areas, and if
you've heard any comments by users on the air about
the system coverage.

Most mountain agencies are not using DTRS yet but the fringe mountain counties like Jefferson County seems to be having pretty good luck. You still here CSP say pretty frequently you were digital please repeat.

Jim<

 

[Thayne]

IMHO, I don't think the mountain sites are anywhere near complete yet, especially the north side of the western slope--So time will tell.

 

[poltergeisty]

800 mhz. bahhh humbug!!!!

Why don't they just use vhf or uhf? They always have to complicate things. Dose not make any sense to me seen is how that band is right near cell phone bands and with 800 Mhz. Theres a more likely hood of the signal attenuating then with a vhf or uhf system coupled with a digital modulation throw qpsk in there and I think it's even worse. They could of at least tried to use 600 Mhz. My thought on the 800 Mhz. is that it is a stupid idea. In fact I think a lot of metro areas hate it do to the attenuating principal of 800 Mhz. I read that fdny went back to it's regular system becuse of problems. The only thing I see that sheds a ray of light out of this mess of a system is the ability to inter communicate with deferent agency's. And you can do that with any system. I whant to know the who, what, where and why and some times how 800 Mhz????? :x I think some nume skull scrated his head and said gee why don't we through public safty right there with cell phones and experimental signals and wi -fi and the rest of the crap 800 Mhz. has become all ready. Thanks FCC :roll: You know the faa stands for Felt Another Ass. while the fcc standsd for Feeding off of Corporate Check books. :wink:

 

[jimmnn]

Re: 800 mhz. bahhh humbug!!!!

Why don't they just use vhf or uhf? They always have to complicate things. Dose not make any sense to me seen is how that band is right near cell phone bands and with 800 Mhz. Theres a more likely hood of the signal attenuating then with a vhf or uhf system coupled with a digital modulation throw qpsk in there and I think it's even worse. They could of at least tried to use 600 Mhz. My thought on the 800 Mhz. is that it is a stupid idea. In fact I think a lot of metro areas hate it do to the attenuating principal of 800 Mhz. I read that fdny went back to it's regular system becuse of problems. The only thing I see that sheds a ray of light out of this mess of a system is the ability to inter communicate with deferent agency's. And you can do that with any system. I whant to know the who, what, where and why and some times how 800 Mhz????? :x I think some nume skull scrated his head and said gee why don't we through public safty right there with cell phones and experimental signals and wi -fi and the rest of the crap 800 Mhz. has become all ready. Thanks FCC :roll: You know the faa stands for Felt Another Ass. while the fcc standsd for Feeding off of Corporate Check books. :wink:

As I'm sure your well aware the APCO-25 communications standards are mandating the move to 800MHz trunked and most local, state and federal grants are only available now for that equiptment and not VHF/UHF.

Jim<

 

[k0pwo]

actually that isn't quite true... The FCC mandate which started many years ago is for all agencies to move to narrowband transmissions standards. From 25khs to 12.5 then to 6.25 and eventually to 3 something. The only way to do this is thru going digital which can narrow the band width of a transmitted signal enough to make the standards. The mandate was never to hide communications from hobbiest or the public, but was to converse spectrum space. The fcc wanted most agencies to go to 800mhz, but all vhf and uhf freqs are available for apco 25 trunked or conventional.

Dave

 

[poltergeisty]

why would the fcc want them to go 800 Mhz?

 

[k0pwo]

Back when the fcc wrote the original mandate. They thought that the spectrum would support all the agencies throughout the US when the bandwidths were narrowed. They apparently never thought about the fact that cellphones and nextel would cause so many problems and that the propagation chartieristics of 800mhz would be so bad in buildings and such. There hope back then was that smr's and the like would populate the vhf and uhf areas of the bands and that all public safety would be on 800mhz. However, as we know now.. it didn't and will not work that way.

 

[INDY72]

Thus the opening of 700 MHz in sddition to the rebanded 800 MHz,..

APCO P-25 is not only for these, but also UHF, and SNFM VHF Hi.... As was stated,... And additionally, with true P-25 systems,.. they are all interoperable, be it VHF Hi, UHF, or 700/800. Thus the whole point really of APCO P-25, everyone able to talk to each other. As to cellular, I have not heard of much in the way of it interfering with PS systems.. Nextel SMR sure,.... but that is being fixed with the 800 MHz rebanding.

As to why 800 MHz?- Back when all the planning was being done for a lot of the Statewide systems,... 800 was the big dog,... Now of course there are some VHF Hi systems comming online,... but the majority of the Statewide TRS's is 800 MHz....

Colorado, Oklahoma, South Carolina, North Carolina, Louisianna, the planned Tennessee TRS, Florida, Arkansas.... The growing Georgia system... Hope that helps

 

[rfburns]

Coverage is good where the system has been built out. One coverage hole on the East Slope is South of Cripple Creek. Faded reference sensitivity (FRS) issues cause high BER's which result in dispatchers saying you went digital. FRS will be a big issue in the Colo terrain. Using antennas with some downtilt helps, but that decreases the signal strength out at the horizon. Japanese RF enginners and others have been in Colo trying to find a fix for FRS. It's not just an 800 issue, but happens with UHF and VHF digital systems as well. High level background noises cause problems, like in firefighting when saws are running. The C4FM vocoders get confused with the background noise. That's why digital doesn't work well for fireground chs. Some sites don't have enough chs for the amount of loading resulting in busy bongs. As long as the federal govt keeps sending grant dollars more chs and sites will keep being added to the system.

 

[poltergeisty]

Ok I understand this a lot better now. So theres no thinking ahead when it comes to making a move. Not very chess like. Sounds like whats happing in Irag. (Meaning no planing ahead example falluja. sob got a way.) I think that alot of critical desecions need to be well thought out. It seems to me that the fcc can't keep control of how a band is spose to be used. I'snt that why the fcc was created? It's doesn't surprise me that they would go ahead and use another part of the spectrum for there mistake hope this time they get it right. Don't they no anything about frequency propagation chartieristics and other things concerning rf? I always thought they did. I think one band be dedecated to public safety and that be it. Or at least half say 700-750. That is as simple as it gets. I hear the faa will have a digital trunking system for airlines in the near future. If it (ain't) broke don't fix it. Of course 800 Mhz...... broke, fu.b.a.r, mess up, complete and uder failure.

 

[mikepdx]

Many thanks to all for the replies & discussion.

Perhaps it's a little premature to ask my question.
It might better be asked when the system is
completed statewide in Colo.

I'm hoping you're state's system is not the 'guinea pig'
for the rest of the states that don't yet have a statewide
trunked system.

Michael
Corbett, OR

P.S. I have a sneaking suspicion CSP State-3
will be alive and well for some time to come...