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  #121 (permalink)  
Old 04-25-2014, 1:39 PM
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The above mentioned portable equipment would make a difference for the person wanting to spend big bucks to listen to the Ottawa P25.

I'm not familiar with the XTS5K but I am very familiar with the Motorola 2500. These radios need a system ID to allow access to the host system. So if you want to monitor MARCS, Cleveland, Lucas or Ottawa one would need permission from the system administrator to have an ID for each radio system. Unless you’re in public safety, or receive permission to have a system ID, how will these radios work?
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  #122 (permalink)  
Old 04-25-2014, 2:40 PM
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Originally Posted by 612345 View Post
The above mentioned portable equipment would make a difference for the person wanting to spend big bucks to listen to the Ottawa P25.

I'm not familiar with the XTS5K but I am very familiar with the Motorola 2500. These radios need a system ID to allow access to the host system. So if you want to monitor MARCS, Cleveland, Lucas or Ottawa one would need permission from the system administrator to have an ID for each radio system. Unless you’re in public safety, or receive permission to have a system ID, how will these radios work?
I have friends in Cuyahoga County with XTS2500's, which they programmed (with the Moto software) and they monitor (no transmit) Parma P25, MARCS-IP P25 and GCRCN (Cleveland) P25 systems.

From the conversations I've had with them, I thought that a System ID was only required to belong/join to the system.
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  #123 (permalink)  
Old 04-25-2014, 3:02 PM
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Originally Posted by budevans View Post
I have friends in Cuyahoga County with XTS2500's, which they programmed (with the Moto software) and they monitor (no transmit) Parma P25, MARCS-IP P25 and GCRCN (Cleveland) P25 systems.

From the conversations I've had with them, I thought that a System ID was only required to belong/join to the system.
This is what I've been told also. Receiving is not a problem with these systems. Phase two IP based needs to associate with the system to do both, again this is what I've been told. No flaming, please.
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  #124 (permalink)  
Old 04-25-2014, 3:08 PM
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Just reading through the posts about difficulty receiving and when it does receive its garbled. I live just outside of Oak Harbor and I have to use the attenuator on my Pro 197 with an indoor at or antenna because I get the OH and CC sites at 100% decode just about all the time. If you're getting garbled and its not encrypted, enact the attenuator and see if that helps.

With that said, I work in Portage, Catawba Island and Danbury townships and I have never had an issue with hearing the system in that area using my Pro 197 and a speaker wire J-pole antenna inside the vehicle.
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  #125 (permalink)  
Old 04-25-2014, 4:26 PM
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An old article but has some good info:



THE DIGITAL DIVERSITY OF APCO-25



Despite all the silence you hear while listening to police and fire department radio systems, the public safety spectrum in many locations is quite full. While efforts are underway to allocate new frequency bands, the Federal Communications Commission (FCC) has also been pushing to fit more users in the same amount of space. Their basic plan is to slice up the existing channels into smaller pieces and require users to operate within those pieces. This is a difficult requirement for the older analog radios, but the new digital systems -- including APCO Project 25 -- are prepared for this eventuality.

APCO-25 Modulation

The original APCO (Association of Public-Safety Communications Officials) Project 25 specifications, now a decade old, spelled out two phases for radio operation. Phase I operates in channels that are 12.5 kHz wide, which is the current FCC requirement. However, because the FCC wants to pack more users into the limited spectrum available, they'd like to eventually have everyone using radio channels that are 6.25 kHz wide, or half as much as before. To meet this requirement, Project 25 defined Phase II to operate within 6.25 kHz wide channels.

APCO-25 uses a modulation process called QPSK-c, which stands for Quadrature Phase Shift Keying, continuous. Modulation is just a fancy word for the process of carrying information content over some kind of carrier signal. The transmitter superimposes the information onto the carrier, and the receiver removes the carrier and reproduces the information. Everyday AM (Amplitude Modulation) and FM (Frequency Modulation) radios tune to a carrier signal and retrieve the audio information sent by the radio station.

For Phase I systems, the version of QPSK-c used is called Compatible 4-Level Frequency Modulation (C4FM). When the basic Project 25 specifications were being worked out a decade ago, C4FM was chosen primarily because it provides relatively good efficiency without requiring equipment manufacturers to produce complex and expensive radios. C4FM is designed to operate within a radio channel that is 12.5 kHz wide.

Under the Phase II plan of Project 25, another type of QPSK-c modulation called CQPSK (Compatible Quadrature Phase Shift Keying) is used. It's not all that different from C4FM, but requires a different transmitter and a little more work on the receive side to make things function correctly. The advantage is that it takes up less bandwidth than C4FM, allowing two users to fit where only one did before.

Because C4FM and CQPSK are so similar, the intent was that same basic receiver hardware could properly handle both Phase I (12.5 kHz) and Phase II (6.25 kHz) channels. This means that with modern digital signal processing (DSP) technology, the same scanner hardware should be able to handle both types of modulation.

Digital Simulcasting

As the new APCO-25 scanners make their way into hobbyist's hands, there are reports that they don't work correctly while monitoring some simulcast systems. (Simulcast just means that the same information is transmitted from more than one repeater at the same time, allowing users across a wide geographic area to all hear the same messages.) The symptoms are mainly the inability hear an entire transmission. The first second or two of voice is heard, which then trails off to silence.

To add to your list of acronyms, there is another type of modulation scheme that's used with some multi-site Project 25 systems. Linear Simulcast Modulation (LSM) is a trademarked term for a form of CQPSK that provides a way for receivers to properly handle multiple identical transmissions. It's just different enough that the regular C4FM processing doesn't work correctly.
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  #126 (permalink)  
Old 04-28-2014, 10:23 AM
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I have to say that that's not a very good description of simulcast. Simply put, simulcast uses the same frequencies at each site, synced by usually GPS. MARCS is multi-site, using different frequencies at each site. Yeah, it's cheaper, because the bases don't need to be synced, but it uses up more bandwidth tying up multiple frequencies with the same messages.
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  #127 (permalink)  
Old 04-28-2014, 5:00 PM
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Originally Posted by wd8chl View Post
I have to say that that's not a very good description of simulcast. Simply put, simulcast uses the same frequencies at each site, synced by usually GPS. MARCS is multi-site, using different frequencies at each site. Yeah, it's cheaper, because the bases don't need to be synced, but it uses up more bandwidth tying up multiple frequencies with the same messages.
You might take a look at the database. MARCS has several simulcast cells, including Cuyahoga County, Lake County, Geauga County, Greene County, Washington County and coming soon to scanners near somebody, Franklin County (times three) and Warren County.
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  #128 (permalink)  
Old 04-29-2014, 8:43 PM
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I just ordered my BCD996XT Digital Scanner and WILL be broadcasting (FINALLY) for Ottawa County on Radio Reference (I'm the one broadcasting now, so all that is broadcasting are the fire pages). Easy set up with FreeScan Software. Already set up my buddy's 996XT and it's working great!

Just an FYI for those that have been wondering about when I was going to switch over to the P25 broadcasts.

Thanks!

~Greg
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  #129 (permalink)  
Old 04-29-2014, 10:01 PM
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Thank you!
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  #130 (permalink)  
Old 05-01-2014, 3:45 PM
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Quote:
Originally Posted by wa8pyr View Post
You might take a look at the database. MARCS has several simulcast cells, including Cuyahoga County, Lake County, Geauga County, Greene County, Washington County and coming soon to scanners near somebody, Franklin County (times three) and Warren County.
If they do not operate on the same frequencies at each site, they are not simulcast, by definition. They are multi-site. (Some vendors use different terms for multi-site, but simulcast ALWAYS uses the same frequencies at each site. By definition.)

MARCS is almost exclusively multi-site, except for where they have taken up with a local system, like Lake Co. and Geauga Co. Those are simulcast. Another local example is GCRTA. It is a 900 MHz multi-site system. Not simulcast.
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  #131 (permalink)  
Old 05-01-2014, 9:36 PM
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Originally Posted by wd8chl View Post
If they do not operate on the same frequencies at each site, they are not simulcast, by definition. They are multi-site. (Some vendors use different terms for multi-site, but simulcast ALWAYS uses the same frequencies at each site. By definition.)

MARCS is almost exclusively multi-site, except for where they have taken up with a local system, like Lake Co. and Geauga Co. Those are simulcast. Another local example is GCRTA. It is a 900 MHz multi-site system. Not simulcast.
I'm very well aware of what a simulcast cell is and does since I'm building one. Again, look at the database. Cuyahoga County is a simulcast cell, as are Greene County, Warren County and Washington County. It's not just Lake and Geauga, and there are more coming, including three simulcast cells in Franklin County.

'Nuf said.
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  #132 (permalink)  
Old 05-18-2014, 10:54 PM
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I work at Jerry's C.B. in Millbury, I tryed & tryed & tryed but can't get Ottawa to work. 396XT,996XT'106,197,2096, 96, the to new radios can't get it. Doing something wrong,
maybe someone could stop by. My brain hurt thinking about it. Thanks
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  #133 (permalink)  
Old 05-18-2014, 11:08 PM
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Angry Ottawa Co. Project 25 TRS

I work at Jerry's C.B. in Millbury, about 2 miles from Clay Center, I tryed everything I know and Ottawa Co. P25 wont work, maybe someone can come by and see what went wrong. We have the new radios, and 386XT & 996XT, some Radio Shacks Thanks. Jerry and Dennis
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  #134 (permalink)  
Old 05-20-2014, 10:13 AM
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Thumbs down Ottawa Co. Project 25 TRS

Are you getting a signal at all? I'm only familiar with the Pro-96 you have listed in your radio list. Program in all the frequencies in the data base list then check and see if you are getting a control channel signal and at what percent error. Use the Pro-96 for this. How are you entering the frequencies into the 96? I use the ARC96 software for mine.
I'm 1.5 miles from the Lakeside tower and have problems indoors getting anything with the 96. I can go outside and get a signal but have to find the sweet spot where it's strong enough to work well. I had to install a yagi outside aimed just right for indoor reception and hook it to the 96 and my Uniden to get good signal.
It's a simulcast system and sort of sucks compared to the EDAC and MARCS systems.
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  #135 (permalink)  
Old 05-20-2014, 10:50 AM
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Default Ottawa Co.

I have the 96,197 are set on P25 AUTO , 396,996 P25S don't know, all the other Co. work fine, HP does it on its own, just don't know what to do
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  #136 (permalink)  
Old 05-20-2014, 11:44 AM
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Default Ottawa Co. Project 25 TRS

On the 96 manually step through the channels for Ottawa County in the bank they are in. You should find one that is the data channel. 854.21250c 854.36250c 855.38750c 856.08750c 857.42500c 857.72500c 859.77500c are the frequencies. I'm at work so I can't tell you which one is currently the data channel.
Others have the same problem as you and myself had. It's the nature of the system. It seems if your near the ends of the county the signal sucks.
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Old 05-20-2014, 9:08 PM
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Quote:
Originally Posted by Towman123 View Post
I have the 96,197 are set on P25 AUTO , 396,996 P25S don't know, all the other Co. work fine, HP does it on its own, just don't know what to do
Are you using the FreeSCAN software for programming the Unidens? I used it for mine. I live near Wood/Ottawa border off 579 and I have a hard time picking anything up as well on my 396XT. I did notice the other day while out 51 near Elmore the signal meter for Ottawa Co was showing good. Just never heard any traffic, which could be typical for what I have programmed in.
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  #138 (permalink)  
Old 05-21-2014, 10:04 AM
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Default Ottawa Co. Project 25 TRS

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Originally Posted by firenresq77 View Post
Are you using the FreeSCAN software for programming the Unidens? I used it for mine. I live near Wood/Ottawa border off 579 and I have a hard time picking anything up as well on my 396XT. I did notice the other day while out 51 near Elmore the signal meter for Ottawa Co was showing good. Just never heard any traffic, which could be typical for what I have programmed in.
I was using a Uniden 796D for a while with a ST2 but couldn't get anything even with 3-4 bars. My 96 and PSR800 couldn't get anything indoors but if I found the sweet spot outside worked great. Using a yagi gives me full bars on all 3 scanners indoors.I know on the 796 I need full bars to get it to work right. When the wind blows my yagi (home made) and it flexes a bit and one bar drops out on the 796 I get nothing. The 800 and 96 handles the drop just fine.

Using the 800 with the Radio Shack 800mhz antenna while driving around Danbury is hit and miss.
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  #139 (permalink)  
Old 05-21-2014, 10:15 AM
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What kind of radios are they using for the Ottawa county P25. I have some kenwood P25 radio wonder if I can monitor them with it.
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  #140 (permalink)  
Old 05-21-2014, 10:33 AM
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Default Ottawa Co. Project 25 TRS

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Originally Posted by bucknut937 View Post
What kind of radios are they using for the Ottawa county P25. I have some kenwood P25 radio wonder if I can monitor them with it.
Not positive but I've hear they are Harris P7100 and P7200 simulcast.
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