Manchester P25 System

[jrothwell]

Fire dept doing radio tests on tg 10019, assuming they are prepping to go Live for next week. Radio ID was coming up as 0. Is this common?

I was listening to that as well. It may have showed up as 0 on your scanner because they were testing their emergency buttons and the scanner may not be able to decode this properly. My XTS2500 received the emergency signals properly, and displayed the proper text and radio IDs. They were also testing a patch to the old system. I imagine this will be similar to when PD migrated over; audio patched from new to old until all mobile radios are swapped out.

 

[Dave2582]

Ahh ok. Once complete, then it should show the correct ID.

 

[NFR85]

TAC channels for FD cannot be heard. Only able to hear dispatch. Are they encrypted as well?

 

[NFR85]

TAC channels for FD cannot be heard. Only able to hear dispatch. Are they encrypted as well?

Squelch was not set correctly

 

[centromere]

What are the CC and voice frequencies in use right now? Why did they set up a brand new system with phase I instead of phase II, given FCC requirements going in to effect in 2017?

 

[ecps92]

What FCC Requirement ?? Please cite the CFR

What are the CC and voice frequencies in use right now? Why did they set up a brand new system with phase I instead of phase II, given FCC requirements going in to effect in 2017?

 

[radioman2001]

Per FCC in 2013 phase II no longer required anytime soon, as in the next 10 years for 700 mhz. Other band never been a requirement, so why pay an additional 40% more for Phase II on your system for something you may not need.

 

[jim202]

Per FCC in 2013 phase II no longer required anytime soon, as in the next 10 years for 700 mhz. Other band never been a requirement, so why pay an additional 40% more for Phase II on your system for something you may not need.

Unless someone knows something different, all the new repeaters being installed by the radio vendors around the country these days are capable of phase 2. They are able to transmit phase 2 initially. If a radio programmed with a phase 2 talkgroup transmits, they will repeat in the phase 2 mode. But I think you will find that most of the user radios will be programmed with phase 1 talkgroups.

 

[centromere]

What FCC Requirement ?? Please cite the CFR

I didn't realize that they reversed the mandate:
FCC eliminates 700 MHz narrowbanding mandate, reserves channels for T-Band, air-to-ground comms | FCC content from Urgent Communications

“We conclude that the December 31, 2016 narrowbanding implementation deadline is no longer viable,” the FCC report and order states. “The record indicates that requiring narrowbanding by December 2016 would force many licensees to modify or replace existing systems well before the end of their useful life. In addition, we share the concerns expressed by many commenting parties about the maturity of 6.25 kilohertz-capable equipment, including the lack of developed open standards governing major system components.”

 

[NFR85]

Day 2 of Fire going live I'd say the audio is 100% clearer than the EDACS. No breakups.

 

[Dave2582]

Yeah, I heard some transmissions last night and some this morning. Sounds a lot better than pd

 

[centromere]

Day 2 of Fire going live I'd say the audio is 100% clearer than the EDACS. No breakups.

Do you know what frequencies and talk groups they are operating on (control channel, voice channel, etc)?

 

[Dave2582]

Do you know what frequencies and talk groups they are operating on (control channel, voice channel, etc)?

Load up the frequencies and tgs found here

City of Manchester Trunking System, Manchester, New Hampshire - Scanner Frequencies

 

[Dave2582]

What is the tg 10001?

Sounds like fire dispatch, but no ID on what this tg is...

 

[centromere]

Load up the frequencies and tgs found here

City of Manchester Trunking System, Manchester, New Hampshire - Scanner Frequencies

How did people determine that 858.2125 was the primary control channel? My expectation is that the control channel constantly broadcasts, but that's not what I am detecting (see attached). I am detecting constant output at 859.4875, which is one of the frequencies on their FCC filing.

 

[Dave2582]

I believe when a new system is first put in place, it needs a control channel to start. When the radio techs first installed it, they picked a frequency that the city has and put it to use. Freq 858.2125 was picked. My understanding that they needed another freq or 2 to be a voice channel. So the techs picked a couple within the pool of frequencies that the city has. As the build out progressed, the techs changed up the control channels and alternate cc were introduced. But 858.2125 is the first born, so that will always remain the primary cc. This is totally my understanding and anyone feel free to correct me otherwise. As long as you are reading that page, the red (primary) and the blue (alternate) frequencies should be loaded up as well as the other frequencies.

 

[centromere]

I believe when a new system is first put in place, it needs a control channel to start. When the radio techs first installed it, they picked a frequency that the city has and put it to use. Freq 858.2125 was picked. My understanding that they needed another freq or 2 to be a voice channel. So the techs picked a couple within the pool of frequencies that the city has. As the build out progressed, the techs changed up the control channels and alternate cc were introduced. But 858.2125 is the first born, so that will always remain the primary cc. This is totally my understanding and anyone feel free to correct me otherwise. As long as you are reading that page, the red (primary) and the blue (alternate) frequencies should be loaded up as well as the other frequencies.

How do you know that 858.2125 was chosen? Was is communicated to you by a city official, or did you measure it with (say) a USRP?

 

[Dave2582]

Well, for instance, someone with inside knowledge communicated on this forum in particular and let us know that a new system is in place with the 858.2125 freq being used as the primary cc. If this wasn't the case, people in the area monitors frequencies and will hear the noise that you heard, and would monitor closely with a unitrunker software that would show the development of the new system being built with additional frequencies that pop up.

Another giveaway is that the city announced that they would be using the same frequencies as the old system. They would slowly add on the frequencies when the system becomes ready (radios put in cruisers, portables are programmed).

 

[centromere]

Well, for instance, someone with inside knowledge communicated on this forum in particular and let us know that a new system is in place with the 858.2125 freq being used as the primary cc. If this wasn't the case, people in the area monitors frequencies and will hear the noise that you heard, and would monitor closely with a unitrunker software that would show the development of the new system being built with additional frequencies that pop up.

Another giveaway is that the city announced that they would be using the same frequencies as the old system. They would slowly add on the frequencies when the system becomes ready (radios put in cruisers, portables are programmed).

In that case, I don't understand why my spectrum shows no peak at 858.2125.

 

[ecps92]

Control Channels Can and Do Change.
Depending on who and how it was programmed in the older systems it might rotate every 24 hrs, with the newer P25 Systems, any of the allocations could be the CC

When the system first came up a quick search of 850-869 found the CC
There is also software, that can read the data stream (Search for Trunker and Unitrunker)

In that case, I don't understand why my spectrum shows no peak at 858.2125.