MOTOTRBO/P25 Decode Success

Status
Not open for further replies.

fredva

Member
Feed Provider
Joined
Mar 19, 2007
Messages
1,691
Location
Virginia/West Virginia
Congratulations!

Thanks for sharing that info. I was just wondering: Have you been able to successfully decode Madison County Sheriff's Office? I imagine it would big help to others if you share whether some of these MOTOTRBO public safety channels could be heard or if they were encrypted (scrambled). If they aren't encrypted, more people might be motivated to pursue the DSD option.
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
Work in Progress

Thanks for sharing that info. I was just wondering: Have you been able to successfully decode Madison County Sheriff's Office? I imagine it would big help to others if you share whether some of these MOTOTRBO public safety channels could be heard or if they were encrypted (scrambled). If they aren't encrypted, more people might be motivated to pursue the DSD option.
I knew that question would be asked sooner or later. Assuming the Madison Co. SO transmitter site is on Fork Mtn., that is approximately 120 air miles from my location in south central Va. But I do receive the STARS P25 transmission from Fork Mtn. strong enough to decode. I occasionally hear the Madison Co. SO MOTOTRBO on 154.8000 mhz. but their transmissions tend to be short and infrequent. Additionally there are a couple of analog users in MD or NC also on that frequency I hear who are stronger and easily override the Madison Co. SO transmissions. Currently other digital formats reception testing and MOTOTRBO "fine tuning" actions are my higher priority.

In my opinion there is no one "cookie cutter" equipment configuration for successful reception. The computer's cpu speed, sound card and unfiltered MOTOTRBO audio signal must be "worthy". Only experimenting determines whether or not successful reception is realized. You see on the forum link only part of what I went through. There was more email help correspondence involved. But now I know what to do to make my setup work.

Like it or not MOTOTRBO is here to stay and is a cost effective alternative for some public service and business users to have a digital radio system who cannot afford a more expensive digital trs. If a signal is "private" it cannot be decoded.

If I successfully receive the Madison Co. SO I probably will make a post on the Va. forum.

John
W4UVV
 
Last edited:

dtscho

Member
Database Admin
Joined
Aug 7, 2001
Messages
1,743
Location
Fredericksburg, VA
I can confirm that Madison is not using privacy on 154.8000. Running the DMRDecode program on the signal, here is the information I've obtained:

Color Code 1
Time Slot 1
Group 30901

Orange Sheriff has switched to TRBO on 155.3700 and 155.6850 as well. Here is the information for those two frequencies:

155.3700
Color Code 1
Time Slot 1
Group 10900

155.6850
Color Code 1
Time Slot 1
Group 10902

These two frequencies are not using privacy either. All three should be monitorable using DSD.

Dave
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
Good News

I can confirm that Madison is not using privacy on 154.8000. Running the DMRDecode program on the signal, here is the information I've obtained:

Color Code 1
Time Slot 1
Group 30901

Orange Sheriff has switched to TRBO on 155.3700 and 155.6850 as well. Here is the information for those two frequencies:

155.3700
Color Code 1
Time Slot 1
Group 10900

155.6850
Color Code 1
Time Slot 1
Group 10902

These two frequencies are not using privacy either. All three should be monitorable using DSD.

Dave
Tnx. That's good news.

John
 

fredva

Member
Feed Provider
Joined
Mar 19, 2007
Messages
1,691
Location
Virginia/West Virginia
Thanks for the info. Until now, I hadn't seen anything definite on whether Orange and Madison were using encryption. But I have seen people asking questions about how and if those systems could be received.
 

kc4jgc

Member
Joined
Mar 7, 2004
Messages
1,481
Location
Virginia Beach, VA
Wirelessly posted (SAMSUNG-SGH-T459/T459UVIA1 NetFront/3.4 Profile/MIDP-2.0 Configuration/CLDC-1.1)

W2NJS said:
Has anyone noticed that, while the listed title of this thread is P25 it's actually about TRBO?
Look again....
 

radiomanNJ1

Member
Joined
Aug 16, 2008
Messages
789
Location
In the land of make believe
Is the DMRDecode program available for download?

I can confirm that Madison is not using privacy on 154.8000. Running the DMRDecode program on the signal, here is the information I've obtained:

Color Code 1
Time Slot 1
Group 30901

Orange Sheriff has switched to TRBO on 155.3700 and 155.6850 as well. Here is the information for those two frequencies:

155.3700
Color Code 1
Time Slot 1
Group 10900

155.6850
Color Code 1
Time Slot 1
Group 10902

These two frequencies are not using privacy either. All three should be monitorable using DSD.

Dave
 

W2NJS

Member
Joined
Mar 27, 2006
Messages
1,938
Location
Washington DC
You guys kill me. The thread title is Mototrbo/P25 but nowhere do I see anyone talking about P25.
That is the point of my remark, unless some poor uninformed soul thinks that the two modes are the same thing, which of course they're not.
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
There's always one

You guys kill me. The thread title is Mototrbo/P25 but nowhere do I see anyone talking about P25.
That is the point of my remark, unless some poor uninformed soul thinks that the two modes are the same thing, which of course they're not.
If you or anyone read my first post on this subject they will understand. It is a link to a another forum thread that documented my trials and tribulations attempting to decode MOTOTRBO signals. Subsequently in tuning vhf/uhf using DSD software additionally some P25 signals were decoded hence the title of this thread "MOTOTRBO/P25 Decode Success". The two threads are subject interrelated.

Only you have posted a leap of logic that the two modes are the same. Do not falsely assume everyone reading this thread is ill informed and will react as you did.

As to the point of your remarks apparently you are the only one who cares and falls under the category "Waste of Time". You're attempt to cause controversy or argument didn't work. Glad we "killed you".
 

fredva

Member
Feed Provider
Joined
Mar 19, 2007
Messages
1,691
Location
Virginia/West Virginia
Valid title

You guys kill me. The thread title is Mototrbo/P25 but nowhere do I see anyone talking about P25.
That is the point of my remark, unless some poor uninformed soul thinks that the two modes are the same thing, which of course they're not.
If you had followed the link included in the original post and read through it, you would have seen statements such as "Tuning several of the VA. vhf frequencies for the statewide digital STARS radio system I heard P25 audio on several active voice repeater systems." The title of this thread is completely valid - the original poster was talking about MOTOTRBO and P25. After the first post in this thread, I asked a question specifically about MOTOTRBO systems, but that doesn't make the title of the thread invalid.
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
Madison Co. SO Reception Success

Thanks for sharing that info. I was just wondering: Have you been able to successfully decode Madison County Sheriff's Office? I imagine it would big help to others if you share whether some of these MOTOTRBO public safety channels could be heard or if they were encrypted (scrambled). If they aren't encrypted, more people might be motivated to pursue the DSD option.
I heard a Madison Co. SO traffic stop comm today at 1220 EDT on 154.8020 mhz.(best reception) MOTOTRBO positive polarity.

I have no way of knowing for sure but I believe I was receiving the Aroda, Madison Co. site transmissions which is about 95 air miles WNW of my location.

John
W4UVV
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
Learn by doing

How do u decode it
First I recommend you get educated (i.e., learn) as much as possible about digital signals reception in general and specifically MOTOTRBO. Read the RR Wiki links on the subject and all previous RR posts on the subject to include all links within this thread. Do Google searches on the subject. Assemble the necessary system components that technically are "worthy" for decoding digital signals. Make any equipment modification required. Download the appropriate RR Wiki link software. Last learn by doing/experimenting as I did. If you need help ask in the digital voice decoding software forum not here.. Digital signals reception is not as forgiving as analog reception. Like the weakest link in a chain determines its strength, the configuration equipment components used will impact audio reception quality. Receiving MOTOTRBO digital signals additionally requires the correct polarization of the received signal (i.e., either positive or inverted) and MOTOTRBO has a "private" user option which basically encrypts the signal..

MOTOTRBO and other digital radio system baselines are here to stay and are a cost effective option for some public service and business users. MOTOTRBO will not be a user selection feature in some new scanner model.

In the central Va. area so far I have logged 19 MOTOTRBO users one of whom uses a 2 channel trunked system.
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,618
Location
Prince George, Virginia--Central Va.
MOTOTRBO Finds So Far

Could you list the MOTOTRBO users you've logged? Thanks.

Dave
Per your request attached is a screen capture of MOTOTRBO signals received so far. It's a time consuming work in progress effort. As with analog and NBFM comms MOTOTRBO comms also tend to be infrequent, short and non-descriptive. Additionally licensing information may not be available in the FCC database for every MOTOTRBO comm heard. Why I do not know.. Also I may be hearing a couple of signals more distant than my typical central Va monitoring area. Two good DMR signals that frequently system poll with no audio heard so far are in the 454-455 mhz. assigned paging range. They are not analog or digital paging signals.

Probably 90% of MOTOTRBO systems in central Va. are leased or sold and installed by Commtronics who also provides maintenance support. Notice three MOTOTRBO users are licensed to Commtronics. The two taxi companies definitely are in Richmond as I recognized some of the street locations. Both use van type vehicles and service the entire metro area. The licenses to Commtronics were no mistake. Most likely there were done purposely. Some taxi operations monitor their competitor's radio transmissions and occasionally "steal" their customers by arriving first at the dispatched location. On past occasions fist fights have occurred between taxi drivers because of such "stealing". Anyone searching the FCC database would never find a license in that taxi company's name and location. Additionally even if someone did know the taxi's operating frequency and listened he would hear only the MOTOTRBO analog braaap audio.. This clever method of operation adds a layer of privacy protection to the radio user.

John
W4UVV
 
Last edited:

SCR584

Newbie
Premium Subscriber
Joined
Jan 20, 2013
Messages
4
Location
Dayton Oh
Does anyone have Greene County Talkgroup numbers?

Does anyone have the Greene County talk group numbers?
 
Status
Not open for further replies.
Top