New Linn County P25 HELP

[dgmaley]

Dave.................are you listening to me
SIMULCAST = ALL towers transmit the same information.

The design is so EVERY car in LINN County can talk together no matter where they are...........INCLUDING in Johnson county
since the system is identical

Oh yes, I am listening.
So, every tower will have to handle traffic from Linn County, Johnson County, Cedar Rapids, Marion, State interconnect and some odds and ends, all at the same time. I only see twelve available voice channels. I surrender, what am I missing? This will be a long list of group codes where only a small percentage can be active at any one moment.
On any normal day, the percentage of utilization is low and a large number of groups are handled. Much like a cell phone network. Consider what might happen on a not normal day and when was your last one?
Dave...

 

[IowaGuy1603]

The system is well designed by a company that knows what they are doing................

A scanner listener is not going to hear Johnson County cars on the Linn System, but a Harris radio in a police car would be able to access it if necessary

Linn County system cars will normally be on a Linn County tower and like wise with Johnson county system cars.

I don't know the details of HOW the system works but I trust Racom to make it work and Dave Knott to have overseen the system design so it WILL work

 

[dgmaley]

Too Much

The system is well designed by a company that knows what they are doing................

A scanner listener is not going to hear Johnson County cars on the Linn System, but a Harris radio in a police car would be able to access it if necessary

Linn County system cars will normally be on a Linn County tower and like wise with Johnson county system cars.

I don't know the details of HOW the system works but I trust Racom to make it work and Dave Knott to have overseen the system design so it WILL work

Yes, I agree. It is well designed. But, you are still repeating history. 99.9% of the time there will be no issue. But ^&$#@&* will still hit the fan around once every two years. It's the physics of a shared resource. That's why us communications techs keep old documents and emails. It's CYA.
Actually this system may go out to three or four nines (99.9999%) Each additional nine raises the price a bunch. Four nines means the fan only gets hit once every five years.
If you want to see an administrator get mad, when he comes in and yells that the network is DOWN, just tell him then cheer it up.

 

[IowaGuy1603]

Yes, I agree. It is well designed. But, you are still repeating history. 99.9% of the time there will be no issue. But ^&$#@&* will still hit the fan around once every two years. It's the physics of a shared resource. That's why us communications techs keep old documents and emails. It's CYA.
Actually this system may go out to three or four nines (99.9999%) Each additional nine raises the price a bunch. Four nines means the fan only gets hit once every five years.
If you want to see an administrator get mad, when he comes in and yells that the network is DOWN, just tell him then cheer it up.

whatever

 

[jfinkstein]

Hi Joe;

There are several PRO 96's in town. Can you get it to decode any P25 system? I do know it was made for RS by GRE. GRE scanners use a separate DSP chip just to decode P25 audio. If yours had a firmware update that was not done correctly the decoder won't work. The CPU and the DSP chip must both be updated and in the proper order.
Talk to Phil K0PAS. He has one that was decoding CRPD system.
Dave...

Dave...I have been decoding CRPD trunking for years on my Pro96. My problem is I just can't decode the audio on the new P25. I have upgraded the DSP APP to the latest version U4.1. However, from what I read, it appears that the CPU and DSP VOICE cannot be upgraded. If that is the case, it may not work. I just did the Saturday download again from RR, but I am not sure if this is the Saturday update you mentioned earlier.
Joe W0MJN

 

[dgmaley]

New System

Dave...I have been decoding CRPD trunking for years on my Pro96. My problem is I just can't decode the audio on the new P25. I have upgraded the DSP APP to the latest version U4.1. However, from what I read, it appears that the CPU and DSP VOICE cannot be upgraded. If that is the case, it may not work. I just did the Saturday download again from RR, but I am not sure if this is the Saturday update you mentioned earlier.
Joe W0MJN

Joe;
If you can decode the CRPD system with the current firmware, you should be OK. The firmware should be able to decode the new system. It still uses the same P25 system voice. I have mostly garbled audio from Linn Co because it is a simulcast system. There's multiple towers that send out the same data. This causes timing issues in the scanners. A 9 element 800Mhz yagi is on its way to narrow down the signal source. Wondering if you might be having the same issue?

ZZG

 

[dgmaley]

New System

Well, I waited for the update...wiped my scanner clean and re-loaded...still nothing from the P25 system :-( I will try again tomorrow in case there is something else getting updated tonight.

I did the same here to a PSR800. Built a new VFolder and loaded it with only Law and Fire from today's update. It only loaded talk groups that are not encrypted for the sheriff and Marion and a few others. I'm listening to it right now. The Cedar Rapids system is yak yak yak while Linn Co has little use. But LinnCo is there. Wonder if you might also be having issues with signals from multiple towers.

Dave..

 

[timkilbride]

The system is well designed by a company that knows what they are doing................

A scanner listener is not going to hear Johnson County cars on the Linn System, but a Harris radio in a police car would be able to access it if necessary

Linn County system cars will normally be on a Linn County tower and like wise with Johnson county system cars.

I don't know the details of HOW the system works but I trust Racom to make it work and Dave Knott to have overseen the system design so it WILL work

Actually, when a Johnson County radio affiliates with the controller for Linn County, his Johnson county traffic is repeated on the Linn County towers. With that, if you have the Johnson County GID's are programmed into your scanner, under the Linn County system, you will hear Johnson County. The last Johnson County traffic from Law 1 was 2356 yesterday and Law 3 was 2349.

Regarding radio reliability, I have heard a couple different officers complain there "calls" were not heard. One situation was in Marion and the other was in Ely inside the fire station.

Tim

 

[IowaGuy1603]

Actually, when a Johnson County radio affiliates with the controller for Linn County, his Johnson county traffic is repeated on the Linn County towers. With that, if you have the Johnson County GID's are programmed into your scanner, under the Linn County system, you will hear Johnson County. The last Johnson County traffic from Law 1 was 2356 yesterday and Law 3 was 2349.

Of course...........I mis spoke the mechanics

But you said the operative phrase when you mentioned that the scanner has to have the JCOM GID's programed..................if you don't have them in the LCOM system, you won't hear them.



as far as the reliability....................I still hear complaints from Cedar Rapids officers on their system and that has been working for a number of years........................There are going to fall outs in any system

and the other was in Ely inside the fire station.Tim

That would be a rough one .............seriously the location is terrible for any of the towers being it JCOM or LCOM. Too many hills and valleys between Ely and Solon, Swisher, Palisades and/or Berry Rd---------Then being inside a sheet metal building

But I would imagine that over the course of the next couple months they will tweak the system a bit too.

 

[IowaGuy1603]

Dave...I have been decoding CRPD trunking for years on my Pro96. My problem is I just can't decode the audio on the new P25. I have upgraded the DSP APP to the latest version U4.1. However, from what I read, it appears that the CPU and DSP VOICE cannot be upgraded. If that is the case, it may not work. I just did the Saturday download again from RR, but I am not sure if this is the Saturday update you mentioned earlier.
Joe W0MJN

You have some setting wrong................the Pro 96 CAN decode the system.

Sorry I can't help you with the settings because I only have GRE 800's-----but I know there are people who are listening to the JCOM system with Pro96's

Yes the Saturday Update from RR is what he was talking about...............it had the correct TG's for what is currently on the system.

Sorry I can't help more ------------------I would ask around

 

[dgmaley]

Who complains the most?

as far as the reliability....................I still hear complaints from Cedar Rapids officers on their system and that has been working for a number of years........................There are going to fall outs in any system


You are absolutely right.
It has nothing to do with analog or digital. It's the nature of RF.
Just moving six inches may be all that's needed, especially at 800Mhz.
Hand held radios are famous for that. Assume the Statue of Liberty position when using a hand held on the fringe.

Still, who complains the most about the radio system?

Dave.

 

[IowaGuy1603]

Still, who complains the most about the radio system?

Dave.

Since we went Narrow band our VHf system has about 70% of the range and reliability as when we were wideband.

 

[Tmartcr]

has any one been able to get this system to decode using SDR# unitrunker and dsd? I get the control channel data etc to populate unitrunker but never get any voice decode

 

[dgmaley]

Since we went Narrow band our VHf system has about 70% of the range and reliability as when we were wideband.

Willing to bet you had the existing radio equipment narrow banded instead of being replaced...

 

[jfinkstein]

You have some setting wrong................the Pro 96 CAN decode the system.

Sorry I can't help you with the settings because I only have GRE 800's-----but I know there are people who are listening to the JCOM system with Pro96's

Yes the Saturday Update from RR is what he was talking about...............it had the correct TG's for what is currently on the system.

Sorry I can't help more ------------------I would ask around

Thanks. I did the RR update today, but nothing has changed...still no audio. I need to determine what setting for the PRO 96 is not set correctly.
Joe

 

[IowaGuy1603]

Willing to bet you had the existing radio equipment narrow banded instead of being replaced...

Well of course...............the radios were bought with narrow banding in mind. One of the reasons that we bought the radios to begin with was the ability to be narrow banded.

 

[IowaGuy1603]

deleted -----

 

[Tmartcr]

Well of course...............the radios were bought with narrow banding in mind. One of the reasons that we bought the radios to begin with was the ability to be narrow banded.

is jones county repeated i think law is not sure about fire? do they have a voted system?

 

[IowaGuy1603]

is jones county repeated i think law is not sure about fire? do they have a voted system?

Fire is not -
County Ops is

No voter---one site

 

[jfinkstein]

You have some setting wrong................the Pro 96 CAN decode the system.

Sorry I can't help you with the settings because I only have GRE 800's-----but I know there are people who are listening to the JCOM system with Pro96's

Yes the Saturday Update from RR is what he was talking about...............it had the correct TG's for what is currently on the system.

Sorry I can't help more ------------------I would ask around

I wonder if it has anything to do with the Moto 9600 band plan settings (Frequency, offset and Step)