Linn County P25 700/800 .PDF
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Just pure speculation, but from reading the .PDF the whole county would be on it. It also mentioned re-use of the Cedar Rapids TRS frequencies for the new system. I also recall the sheriff sometime back said he wanted seamless interop b/w agencies. The .PDF also talks about the patchs they have now to CR TRS and RACOM.
Tim K.
Tim K.
So I read through this today and wanted to add some information basically if you don't want to read through the whole thing.
* Linn County is looking for a system to run public service and county communications on, but mostly public service (there is an absence of information regarding county maintenance; only city is included)
* According to the document they are willing to consider a non-owned system (RACOM ??).
* There is a lot of legalese about SLAs (Service Level Agreements), warranties on the radios, etc that they require from a vendor.
* They are wanting to use all the existing Linn County / Cedar Rapids repeater sites, they want to add an additional repeater at Glass Road water tower (by adding a free-standing monopole) and they want to discontinue use of the site at Alliant tower
* There is a number of references to issues they experienced during the flood in CR they wish to avoid
* They're also looking to replace the current county UHF paging system
* They're looking to EXPAND the 800MHz 64kbps data system running out of Marion to cover the entire county to supplement cellular data in the officer vehicles.
* They want to add DES based encryption to "at least" one of the public safety talk-groups
There is some technical info on the brands of equipment they're using at different locations, that may be interesting to some readers.
* Linn County is looking for a system to run public service and county communications on, but mostly public service (there is an absence of information regarding county maintenance; only city is included)
* According to the document they are willing to consider a non-owned system (RACOM ??).
* There is a lot of legalese about SLAs (Service Level Agreements), warranties on the radios, etc that they require from a vendor.
* They are wanting to use all the existing Linn County / Cedar Rapids repeater sites, they want to add an additional repeater at Glass Road water tower (by adding a free-standing monopole) and they want to discontinue use of the site at Alliant tower
* There is a number of references to issues they experienced during the flood in CR they wish to avoid
* They're also looking to replace the current county UHF paging system
* They're looking to EXPAND the 800MHz 64kbps data system running out of Marion to cover the entire county to supplement cellular data in the officer vehicles.
* They want to add DES based encryption to "at least" one of the public safety talk-groups
There is some technical info on the brands of equipment they're using at different locations, that may be interesting to some readers.
Looks like a cut and paste from JCOMMMMMMM The City and county doesn't have any money so I can't see this taking off any time soon. They would have to get a lot of money from the Feds maybe it is in the create a job money the gov is handing out?? All I can say is that I can get Marion on 380 to the Black Hawk line. County is about the same. CR goes to about Urbana. Now replacing everyone to digital might look great on paper but they better have the county F-2 users in mind because as it is even a bad VHF signal can be understood most of the time in a emergency a bad digital signal well you hear nothing or a bunch of junk.
I forgot they have those red light cameras and the speed cameras on 380 maybe that will fund it?
I forgot they have those red light cameras and the speed cameras on 380 maybe that will fund it?
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Yes the repeaters tend to travel further because they are often 250w - 1000w, versus the HT and mobile rigs that are between 1 and 50w.
I am sure your concerns are being addressed by those in the county. There is a huge aversion to digital almost everywhere, in the scanner communities, in the public service communities, in the ham communities. I don't understand it, necessarily, but it certainly exists.
IowaGuy1603
Member
In a conventional VHF system the HT's usually run 5 w, mobiles 100 w.
When you get into many trunking systems the HT's are downgraded to 1w and mobiles to 50w because IN THEORY there are more satellite receivers around your coverage area than in a conventional system thus less wattage is needed by the users in the field.
The trouble with drop outs in a trunking system isn't the repeaters------its in the mobiles and their line of sight(and distance) with the receive antenna's of the systme
The aversion to digital in the public service community is driven by the fact that the radio is the "lifeline" for the officer in the field.
Conventional mobile 2 way ----you push the button and talk...........base hears you if you are in range. When it works there is no middle man to get in the way.
Trunking mobile 2 way-----you push the button.............a computer someplace decides if you are important enough to override the user already on the frequency or other factors. There is an extra step in the process that could (and many times does) go wrong. The benefits usually outweigh the downsides and Trunking seems to be much more accepted that it used to be by the end user.
DIGITAL Trunking mobile 2 way adds another step in the process..........actually 2 steps that can go wrong . The digitizing of the signal in the field and the decoding at the base. This is where most public safety officers are resistant. Another computer is in between the officer and potential help.
As more and more systems are in use the benefits will win out in the long run.....................and the officers will learn to trust the system.
Cops don't like change...................they don't trust their lives on new stuff until they understand it works.
I'm not trying to start a flame war but all of those "problems" were eliminated in the 90s. The military has been using trunking since the 70s and digital since the 80s. The bugs have been ironed out. There are plenty of issues that can happen with VHF/UHF systems as well...
- You can be inside a building and not have any coverage, which is the primary reason why these legacy systems are being retired.
- Someone of lesser important can be using the channel and you can't break in with emergency traffic
- The higher powered rigs and continual carrier drains the batteries leaving you without a "lifeline"
- There can be atmospheric ducting generating interference and skip from other repeaters
As for mobile rigs running 100w I assure you that's not true. Maybe some, out in Colorado or something. 35w is pretty standard, 50w is also fairly common.
- You can be inside a building and not have any coverage, which is the primary reason why these legacy systems are being retired.
- Someone of lesser important can be using the channel and you can't break in with emergency traffic
- The higher powered rigs and continual carrier drains the batteries leaving you without a "lifeline"
- There can be atmospheric ducting generating interference and skip from other repeaters
As for mobile rigs running 100w I assure you that's not true. Maybe some, out in Colorado or something. 35w is pretty standard, 50w is also fairly common.
IowaGuy1603
Member
I don't disagree that many of the problems with systems are fixed
I am just saying that many cops still don't trust the system..............that is why they resist. You are the one that said you didn't understand why.............I was just giving my opinion as to why police officers are resistant.
99.99% of the cops on the street could care less about HOW their radio works--------------they just want results when they push the button.
Like I said before.........................cops don't like change.
some of our mobiles radios are 100w models..........(we have a simplex system in Corrections)..........as were my police radios back in the day. Many of the counties that don't have multiple receive sites use the higher wattage mobiles (especially in VHF) to compensate for the distances.
( I just looked in our vans-----------the newest radio was a 50w model.............our older ones are the 100w
It's been a while since I looked in the trunk of a police car...........................................
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IowaGuy1603
Member
The officers that I have personally talked with on LCSO and MPD are basically unhappy with the audio quality of their current digital setup. The administration is unhappy with it for many reasons.............so they hardly ever use the capability they now have. (Neither LC or MPD systems are P25)
I listen in on the CRPD feed and many times hear officers I have known for over 30 yrs and don't recognize their voices nor do I get a feel for the tone of their voice like you can on "clear" transmissions. I haven't really talked to any CR officers on that subject so I don't know their opinions.
I think the transmissions sound like what I remember from putting a string between two tin cans.
Dave Knott, who runs the Linn County radio system is more than slightly aware of those concerns.
I am sure any system that gets the nod will be P25 compliant I also think it is more than a couple yrs down the road.
Even after all the problems during the flood, and all the push to go to a JCOM type center--------------the departmental control posturing (at the administrative level) will keep total interoperability in the distant future.
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I pretty happy with ProVoice audio quality, it is lightyears better than AEGIS. Still not P25-qual but its much better!
IowaGuy1603
Member
Just on the news (KCRG) that Rep Dave Loseback brought a 2.5 million grant to Linn County to help set up a fiber optic network between LC, CRPD, MPD to facilate if one of the stations goes down.
The department that lost comms could go to one of the other PSAP's and just plug in and go to bring up coms..................
The department that lost comms could go to one of the other PSAP's and just plug in and go to bring up coms..................
newsphotog
Member
Guess I was right Fed Stim Money.
Also I wasn't saying that the digital system is to blame, most of the problems are trying to do it on the cheap and cheap doesn't cut it with digital. Just look up Kansas City MO. digital radio problems and you will see what happens when the city went the cheap way and not the right way.
As for the audio of the online feed I can tell you that if they are using a Uniden for the feed it will sound hollow as both of my GRE units sound much more natural. I love the Uniden but wish the audio was better.
Also I wasn't saying that the digital system is to blame, most of the problems are trying to do it on the cheap and cheap doesn't cut it with digital. Just look up Kansas City MO. digital radio problems and you will see what happens when the city went the cheap way and not the right way.
As for the audio of the online feed I can tell you that if they are using a Uniden for the feed it will sound hollow as both of my GRE units sound much more natural. I love the Uniden but wish the audio was better.
Are you talking about the audio on the CRPD feed? I rerouted some wires but nothing else has changed with it. I can't figure out who you were talking to, but if anyone is having issues with the CRPD feed please let me know.
Guess the county will have to find some money the old way tax or fee increase
Funding Crunch, Upgrade May Bring Increase in Linn County E-911 Charge | KCRG-TV9 | Cedar Rapids, Iowa News, Sports, and Weather | Local News
As for the audio I was only saying that the audio can sound different with different scanners I think the GRE sounds better but I love the features of the Uni.
Funding Crunch, Upgrade May Bring Increase in Linn County E-911 Charge | KCRG-TV9 | Cedar Rapids, Iowa News, Sports, and Weather | Local News
As for the audio I was only saying that the audio can sound different with different scanners I think the GRE sounds better but I love the features of the Uni.
I was looking through the .PDF again, below are the TG's/channels programmed into the CRFD radios. Any idea what the "8TAC" channels are? I-Call frequencies??? Looks like there is a analog and a digital version of each one.
Also, the City Wide and ICS TG's are not in the DB, or if they are, not identified correctly.
Tim K.
Fire 1 Dispatch
Fire 2
Fire 3
Fire 4
Fire 5
Airport 1
Airport 2
ICS 1
ICS 2
ICS 3
PD 1 Disp
AAS Disp
St. Lukes 1
MERCY 1
AREA 11
CITY 1
CITY 2
8TAC91
8TAC91D
8TAC92
8TAC92D
8TAC93
8TAC93D
8TAC94
8TAC94D
8CALL90
8CALL90D
IOWA CITY
Also, the City Wide and ICS TG's are not in the DB, or if they are, not identified correctly.
Tim K.
Fire 1 Dispatch
Fire 2
Fire 3
Fire 4
Fire 5
Airport 1
Airport 2
ICS 1
ICS 2
ICS 3
PD 1 Disp
AAS Disp
St. Lukes 1
MERCY 1
AREA 11
CITY 1
CITY 2
8TAC91
8TAC91D
8TAC92
8TAC92D
8TAC93
8TAC93D
8TAC94
8TAC94D
8CALL90
8CALL90D
IOWA CITY
IowaGuy1603
Member
I believe there are a few 800 frequencies set aside for inter op and are supposed to be analog
http://www.sytechcorp.com/products/documents/rios/FCC Designated Interoperability Channels.pdf
http://www.sytechcorp.com/products/documents/rios/FCC Designated Interoperability Channels.pdf
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Awesome find!. The channel tags are the same! The "D" stands for "direct". I was thinking of "Digital".
I wonder if these use for any fireground ops?
Tim K.
This afternoon, headquarters advised all units on TG1617(status bit to TG1616) to use "8Call90" if the radio maintenance outage lasts for more then 1 minute.
I don't have any traffic logged on the 800 tactical stuff so it must have went smoothly.
Tim K.
I don't have any traffic logged on the 800 tactical stuff so it must have went smoothly.
Tim K.
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