P-25 and MA State Police

A forum for the discussion of APCO-2, DMR, NXDN, and any other type of digital radio systems in our monitoring area.
Post Reply
Message
Author
luckyjoe
Posts: 23
Joined: 15 Apr 2009 19:45
Location: Fairhaven, MA

P-25 and MA State Police

#1 Post by luckyjoe » 26 Feb 2013 10:55

Quick question about P-25 and the MA State Police. When I program my scanner for conventional trunking, I program in the CC frequencies, then I program in the talk groups. I noticed in the Wiki that some of the frequencies that are listed for the different zones have P-25 capability. Do you have to program the CC freqs in twice, one for analog, one for P-25? For reference, I live on the SouthCoast (D-Troop).

RKG
Posts: 51
Joined: 28 Jul 2010 16:09

#2 Post by RKG » 26 Feb 2013 11:47

It depends, a) on your receiver and b) on how you are using the term "P25."

There are two distinct flavors of DVSI IMBE digital audio over a Motorola trunked system. One involves dedicated talkgroups, over a SmartNet/SmartZone (sometimes a/k/a "Type II") 3600 baud system, for IMBE voice. Most of the digital talkgroups east of Troop B are of this flavor. The most recent versions of trunking scanning receivers will automatically detect the IMBE voice and decode it properly.

The second is a so-called Astro25 Trunking system, which uses an entirely different, 9600-baud equivalent data stream. All voice on an Astro25 Trunking system is IMBE digital. Being an entirely different system, these systems will use their own set of control channels and voice channels, and have to be programmed as separate systems in your receiver, using the Astro25 protocol. At the moment, there are only two 9600-baud systems operating under the MSP System ID: the new build-out in Troop B's area and a system in, and being used by, Cambridge as a part of Cambridge's migration from analog to digital.

User avatar
pete
Posts: 634
Joined: 29 Aug 2005 20:42
Location: Fall River

#3 Post by pete » 26 Feb 2013 11:51

Short answer, for where you live (D Troop area), NO
Pete :Pats: :sox: :Bruins:
never forget W6 & 343 & C9

User avatar
ecps92
Posts: 4748
Joined: 07 Dec 2005 19:26
Location: South Shore, MA
Contact:

#4 Post by ecps92 » 26 Feb 2013 12:34

All depends on which Zone.

As a general Rule, Anything EAST of the Connecticut River is Not a P25 Trunk. There are P25 [Voice - not Controller] Talk-Groups, but the System itself is Analog
luckyjoe wrote:Quick question about P-25 and the MA State Police. When I program my scanner for conventional trunking, I program in the CC frequencies, then I program in the talk groups. I noticed in the Wiki that some of the frequencies that are listed for the different zones have P-25 capability. Do you have to program the CC freqs in twice, one for analog, one for P-25? For reference, I live on the SouthCoast (D-Troop).
Bill Dunn N1KUG
Cruise Ship Frequencies
http://scanmaritime.com

"The tougher it is to find a frequency, the more it makes me want to work to find it. - I've learned to use the SEARCH Button"

luckyjoe
Posts: 23
Joined: 15 Apr 2009 19:45
Location: Fairhaven, MA

#5 Post by luckyjoe » 26 Feb 2013 15:18

Ok thanks guys for the info. Am new to the P-25 game and slow to absorb it. Understand about trunk systems that are strictly P-25 ie P25 control channels etc. I think I've mastered programming P-25 for reg channels such as New Bedford PD etc. Didn't want to be behind the eightball if Troop D eventually went P-25 or combo with analog. Thanks all again.-----Scott

User avatar
ecps92
Posts: 4748
Joined: 07 Dec 2005 19:26
Location: South Shore, MA
Contact:

#6 Post by ecps92 » 26 Feb 2013 16:20

Longtime away and lots of $$
luckyjoe wrote:Ok thanks guys for the info. Am new to the P-25 game and slow to absorb it. Understand about trunk systems that are strictly P-25 ie P25 control channels etc. I think I've mastered programming P-25 for reg channels such as New Bedford PD etc. Didn't want to be behind the eightball if Troop D eventually went P-25 or combo with analog. Thanks all again.-----Scott
Bill Dunn N1KUG
Cruise Ship Frequencies
http://scanmaritime.com

"The tougher it is to find a frequency, the more it makes me want to work to find it. - I've learned to use the SEARCH Button"

Post Reply