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P-25 and MA State Police

Posted: 26 Feb 2013 10:55
by luckyjoe
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).

Posted: 26 Feb 2013 11:47
by RKG
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.

Posted: 26 Feb 2013 11:51
by pete
Short answer, for where you live (D Troop area), NO

Posted: 26 Feb 2013 12:34
by ecps92
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).

Posted: 26 Feb 2013 15:18
by luckyjoe
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

Posted: 26 Feb 2013 16:20
by ecps92
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