DMRDecode help

[vinsky]

Hi.

I'm using DSD to monitor a local Mototrbo system but all I got is a weird audio while listening to the frequency. I tried to invert polarity in the software and the audio sound change but I can't hear the conversation.

Maybe this system has encryption enable and I would like to use DMRDecode to see if it is private or not. My problem is how to get the software run. I'm on Win 7 and already have it downloaded.

Thanks for your help!

 

[mtindor]

Hi.

I'm using DSD to monitor a local Mototrbo system but all I got is a weird audio while listening to the frequency. I tried to invert polarity in the software and the audio sound change but I can't hear the conversation.

Maybe this system has encryption enable and I would like to use DMRDecode to see if it is private or not. My problem is how to get the software run. I'm on Win 7 and already have it downloaded.

Thanks for your help!

One easy way to know if you need to invert or not is this:

If you did not invert, and the data stream is _always_ showing voice frames, then you need to invert. Let's face it -- no system will have 24/7 voice. But, if you need to invert and you don't invert, DSD will show continuous voice frames.

Once you've ironed out whether or not you need to invert, then you can move on to decoding.

1. Yes, it's entirely possible that you've run across a system or radios using encryption. Although in that case [I can't remember] I think you just won't hear anything.

2. Make sure you aren't overdriving / underdriving DSD. I try to keep it at about 25-30% INLVL. Your mileage may vary, but in my experience things go to hell in a handbasket quickly once you get 10s above or below those values.

I'd suggest in all cases that you use the latest version of DSD [assuming windows] out -- which currently is the 1.6.x Beta. It has a significant bug fixed that in previous versions would cause DSD to crash after a short while. It also has the filtering in it that will significantly improve decoded audio in many cases.

I also am unaware of whether you are using a discriminator tap that you wipped up yourself, or if you are using something that already has discriiminator output (like a PSR-800). If you are using a PSR-800, you should make sure and have the most recent firmware [whether that be the most recent public firmware released in the past six months or the Phase 2 P25 beta firmware]. I say that because in some instances [not with DSD I don't think, but with EDACS monitoring] if using the discriminator audio from the PSR-800, it can affect your ability to get a good EDACS decode.

Mike

 

[vinsky]

Thanks for all the info. I finally got DMRDdecode to work:

DMR Decoder (Build 56)
5:48:01 PM DMR Data Frame
CACH : TACT AT=1 Ch 2 Continuation fragment of LC
Slot Type : Colour Code 1 Idle
5:48:01 PM DMR Data Frame
CACH : TACT Ch 1 Continuation fragment of LC
Slot Type : Colour Code 1 Terminator with LC
Group Voice Channel User LC
Service Options : Non-emergency/Privacy Enabled/No priority
Group Address : 911000 Source Address : 4088


It looks like they are encrypted right?

 

[mtindor]

Thanks for all the info. I finally got DMRDdecode to work:

DMR Decoder (Build 56)
5:48:01 PM DMR Data Frame
CACH : TACT AT=1 Ch 2 Continuation fragment of LC
Slot Type : Colour Code 1 Idle
5:48:01 PM DMR Data Frame
CACH : TACT Ch 1 Continuation fragment of LC
Slot Type : Colour Code 1 Terminator with LC
Group Voice Channel User LC
Service Options : Non-emergency/Privacy Enabled/No priority
Group Address : 911000 Source Address : 4088


It looks like they are encrypted right?

Yes. I'm not sure if that means that each and every group on the system will automatically be encrypted, and thus I'm not sure if it's safe to assume you'll never hear anything on that one. But yes, Privacy Enabled means it's encrypted. I think there are two levels of encryption, but I could be wrong... after all, if we can monitor it, it doesn't make a difference which one it is. But I think there is basic privacy and then a more stout version.

Mike

 

[vinsky]

Yes. I'm not sure if that means that each and every group on the system will automatically be encrypted, and thus I'm not sure if it's safe to assume you'll never hear anything on that one. But yes, Privacy Enabled means it's encrypted. I think there are two levels of encryption, but I could be wrong... after all, if we can monitor it, it doesn't make a difference which one it is. But I think there is basic privacy and then a more stout version.

Mike

Ok thank you for your help. I will try Provoice now!

 

[nd5y]

I got DSD running today and I'm trying to decode the local ProVoice system.
How do you tell if the signal is normal or inverted?
Is there any display data that indicates encryption?
So far I only get stuff like
Sync: -ProVoice mod:GFSK inlvl: 8% VOICE e:====
with varying numbers of = after the e: and garbled audio.
I can't tell if it is encrypted or I'm doing something wrong.

It worked ok on DMR and P25.

 

[vinsky]

Hi Tom. Here I'm using 2 sound cards and 2 scanners for Provoice decoding. I also use Unitrunker to follow the talkgroups and I can see "inverted" in the system info tab. I did not set anything special in DSD about normal or inverted signal. I think it found it by itself. DSD does not display if it is an encrytion enabled system or not. When I receive an encrypted group it's like garbled audio too. I think the system you are trying to listen to is private (encryption) enabled if you can't hear clear voice. The text string you have: Sync: -ProVoice mod:GFSK inlvl: 8% VOICE e:==== looks normal. This is what I get here while listening to the system.

 

[WayneH]

vinsky, I just moved three of your threads to the "Digital Voice Decoding Software" forum. Please create your threads about decoding digital voice in that forum. Thanks.

 

[Forts]

Yes. I'm not sure if that means that each and every group on the system will automatically be encrypted, and thus I'm not sure if it's safe to assume you'll never hear anything on that one. But yes, Privacy Enabled means it's encrypted. I think there are two levels of encryption, but I could be wrong... after all, if we can monitor it, it doesn't make a difference which one it is. But I think there is basic privacy and then a more stout version.

Mike

This is correct. In the example given, group 911000 is using Privacy. Other groups may or may not be as well, as it's not a global setting, it's per group. MotoTRBO privacy has 2 formats, Basic and Enhanced. Basic privacy is a relatively simple (as far as encryption goes) whereas Enhanced privacy uses RC4 with a 40 bit key. Sometime in Q1 2013 they are supposed to be rolling out AES-128 encryption as well.

 

[mainetrunk]

What are you scanning with? I am desparetly looking for the discriminator tap for the pro 106. Can you help me?
thx Ron

 

[Forts]

I use a Pro-106 as well. Look for TP-4 on the main board, that's the point you want. Do a search on here and you should be able to find pictures.

 

[mainetrunk]

I did a straight out search, and found this..Got some crazy looking tech stuff there. I AM science illiterate. Electronic Parts, Components and Suppliers | DigiKey

 

[Forts]

Actually I meant TP-4 on the main board of the Pro-106

Take a look at File:106 photo overlay.jpg - The RadioReference Wiki and you will see what I'm referring to. This is the point that you take the discriminator output from.

 

[mainetrunk]

Dont see any thing like that when I open it--I see2904 k43 jrc on my board, that pic is different?

 

[Forts]

The tap point should be the same in all the 106's... take a look at this thread http://forums.radioreference.com/ra...1-discriminator-tap-pro106-pics-included.html and see if it helps you any. If not, I'll crack open my radio and take a few pictures.

 

[mainetrunk]

sorry, thats not what I see--there are no numbers on the green board-just those black thingee's... 2 metal covers--designed like 2 stores next to each other--no screws there-but the other part is covered by something light gray--rectangular..gettin closer

 

[mainetrunk]

hold on---got back separated--more stuff---looking now

 

[mainetrunk]

ok----so sorry about being illiterate on this stuff---I see it all...Now what goes where-who has it? $$$

 

[Forts]

First off... do you have a soldering iron, and are you handy with it? If no, then you might want to find a friend to do the actual tap for you. If you are handy with an iron it should be a pretty easy process. You will need a couple of resistors, a capacitor and a 3.5mm female plug.

 

[mainetrunk]

Yes I do--no,I dont trust myself.I got a company in Somersworth N.H that did alot of stuff for me in the solderring dept. I for get their name, but they are associated with rfwiz--freq page.. They sold me my ferret. Sooooo, I can get those parts-ebay,sears,ace? Man, am I a slow learner.. Mythbusters says you CAN teach an old ( sea ) dog new tricks..