Mercer County TRS

[CaptDan]

CaptDan are you talking about just fire? The reason I ask is the VSELP on police is not going to be supported by Motorola.

In a word or two - I don't know and don't want to say anything that is incorrect.

I made my comment that Trenton is staying on the 800 Mhz frequencies based upon a recent conversation with people from their Communications Bureau. We were talking about if they were going to the new Mercer County system and they said that Trenton is staying right where they are. I understood this to mean frequency wise, not necessarily equipment manufacturer wise.

The City is in the process of replacing all of the Motorola radios that they bought around 1995 with all new equipment - walkie talkies, mobiles and dispatch consoles. I believe the radio's are Kenwood's.

The fire side is currently simulcasting all 800 Mhz traffic on 460.575

The police side is digital but the only encrypted talk groups are the Vice Enforcement Unit and the Internal Affairs Unit.

Not sure if this helps or just is more confusing.

 

[carbineone]

Just found this for Trenton http://www.trentonnj.org/documents/SC#53764.pdf so it is definately UHF and looks like an LTR trunking system with possible NXDN digital.

 

[phillydjdan]

Nah, I wouldn't bet on LTR. If it's got NXDN capability, my money would be on the system being an NXDN trunked system. If that's the case, good luck listening in. You know, when they went with that weird digital voice format back in the 90's it was for a reason. Privacy. I am willing to bet they go NXDN trunking for the exact same reason.

 

[CaptDan]

I agree - it seems like the information I was given was either incorrect or misunderstood.

Thank you for the correct information

 

[KC2JS]

I see the talkgroups were added to the db. Is this system being used now? Is the system up? I used to be able to get it no problem, now I am not getting a cc.

Thanks.

 

[jetskiman98]

I heard an announcement on the OEM talk group on Thursday stating the system would be unavailable until Monday while there was antenna work done. It said something about migrating to the new system. I've been running unitrunker on it for a while and have seen a ton more activity as of lately. Especially on the new "South Fire Response" talk group. It looks like the control channel went off line Thursday afternoon. Sounds like the entire system will be up and running sooner than expected.

 

[jeff]

From a reliable source inside the FD, Trenton will be going to a 700 mhz Kenwood NXDN system. Interesting that the quote mentions 450-512 mhz, maybe an error from MPS?

 

[carbineone]

maybe it is on the State 700Mhz system ?

 

[carbineone]

I don't think it will be 700mhz . All the new licensing has been UHF under the MPS communications name.
Nothing at all has been applied for 700mhz unless they go with the the Nj state 700mhz system. And definitely not 700mhz NXDN..

 

[CaptDan]

Just curious - why would the City let a private vendor be the license holder ? Is there an advantage to that ? A disadvantage to it ? could the vendor allow other agencies on those frequencies also weather the City liked it or not ?

The city is currently operating a 800 mhz trunked system - is there a technical reason to give up the 800 and switch to 700 or 500 ?

Operationally - because the rest of Mercer County will be in the 500 Mhz area it makes sense to have a radio that could communicate with the surrounding towns.

 

[robbinsj2]

Just curious - why would the City let a private vendor be the license holder ? Is there an advantage to that ? A disadvantage to it ? could the vendor allow other agencies on those frequencies also weather the City liked it or not ?

There may be fiscal advantage and simplicity to the city leasing capacity on a system owned and managed by others rather than putting in the time, effort, and cost (particularly up front) to build their own such system. I'm not in the business but I would be reluctant to build and own/manage a system if I didn't hold the license myself.

I expect the disadvantages to leasing a system rather than building their own can be imagined. Most may be able to be resolved by competitive procurement and and adherence to a good contract with clear terms and requirements of both parties.

Could the vendor allow other users on the same system which the city uses? From a technical standpoint, certainly, and it wouldn't have to be a problem. If the city is concerned about this then it can be addressed in the lease contract.

 

[kdean7]

Mercer has begun training fire officers on the use of the new system.

 

[phillydjdan]

*BUMP*

Any news on the Mercer trunked system? I read the PDF about it, but I am not quite close enough to pick up anything. Did they switch over yet? Any activity at all?

 

[robbinsj2]

Some notes:

A couple weeks ago I heard some department, I think 42, using a new UHF conventional channel for their live burn.

Last weekend I noticed that the trunked system was using a new control channel (500.4500, still active now) and had new system info (WACN, sysid, etc.) but saw virtually no activity on it for the whole weekend. I think there was one key-up and just a couple affiliations. I'm reluctant to submit the info to the database in case this is just temporary and it reverts.

Last weekend there was a continuous tone being transmitted on one of the system channels in P25 modulation, though no indication of it over the control channel. Coverage testing? Not presently active.

Hightstown and the Ch52 tower are simulcasting, I didn't get to check the Ewing site.

Ewing's system license was transferred to the county and the frequencies were all rolled in together, however as of last weekend Ewing still seemed to be operating independently (its own control channel, I didn't check its current emitted sysid and zone).

Jim

 

[NJFirefighter7]

Just too add my two cents I think the switch is great but the radios Kenwood brand a bad choice in taste, they should of made a better choice in Ma/com radios.

 

[phillydjdan]

Some notes:

A couple weeks ago I heard some department, I think 42, using a new UHF conventional channel for their live burn.

Last weekend I noticed that the trunked system was using a new control channel (500.4500, still active now) and had new system info (WACN, sysid, etc.) but saw virtually no activity on it for the whole weekend. I think there was one key-up and just a couple affiliations. I'm reluctant to submit the info to the database in case this is just temporary and it reverts.

Last weekend there was a continuous tone being transmitted on one of the system channels in P25 modulation, though no indication of it over the control channel. Coverage testing? Not presently active.

Hightstown and the Ch52 tower are simulcasting, I didn't get to check the Ewing site.

Ewing's system license was transferred to the county and the frequencies were all rolled in together, however as of last weekend Ewing still seemed to be operating independently (its own control channel, I didn't check its current emitted sysid and zone).

Jim

Very interesting info, thanks!

 

[jetskiman98]

Most of the radios (if not all) that were bought under the grant were Motorola. A few weeks ago I could hear a field unit and the dispatchers at Central reading random phrases to each other. It sounded as if the field unit was driving around testing coverage. I hear someone mention DAQ testing. Some talk around the firehouse sounds like the switch is getting near.

 

[bb77]

I'm trying to get this programmed on my Uniden scanner. Obviously, the system isn't fully implemented so I understand that everything is subject to change.

From what I've read, P25 has implicit and explicit modes. The difference is that for implicit, a band plan/frequency list is needed and some sort of LCN is transmitted over the control channel, where for explicit mode the voice channel parameters are transmitted over the control channel.

This being said, what information exactly do I need to put into the scanner in order to monitor the system? I know how to use groups/TGIDs, but I'm a little fuzzy on the frequency/bandplan configuration. It's hard to test my configuration due to low volume.

I've tried entering the control channels, but I don't see any signal indication and HOLDing while scanning the system doesn't yield control channel audio as it would with an EDACS system for example. Not sure if this is due to improper programming or to differences between P25 and other types of systems.

Thanks!

 

[bailly2]

@bb77. what model uniden do you have? if you search 508 to 509 mhz do you hear a control channel on 508.4875? the system currently has two towers transmitting on the same frequency at the same time (linear simulcast modulation), might get better control channel decoding if you turn up the squelch to hear less of 1 of the 2 towers. simulcasting distortion is a pain, but it is not so bad for me since building my yagi, and using two metal screen like for a window to block out one of the towers and grounding the screens to a heat duct

 

[W2SJW]

Mercer is explicit. As long as it's not a real old model, it will decode the band plan from the CC.