• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

TRX-2: DMR with RAS

Status
Not open for further replies.
Joined
Feb 1, 2003
Messages
880
Location
Pequannock, NJ
#21
You mention a "heartbeat" on the frequency. Is this an IP connect system? What I am listening to is a conventional DMR repeater. No IP Site Connect.

I have set up the TRX-2 scanner locked on the frequency, a PC running DSD+ fed with discriminator audio from a different receiver, and the XPR7550e. DSD+ and the XPR decode 100%. The TRX-2 misses short transmission (10-4, etc) and is slow to unmute on some transmissions.

The CRC issue is Motorola RAS changes the header of the voice packet by injecting an encoded stream of bits for RAS transmissions. That makes the header different from RAS to non-RAS transmissions. This changes the CRC check for the packet.

I've had a Uniden 436. 536, TRX-1, and two TRX-2 scanners and all of those were not 100% in decoding RAS.

Getting back to my original thought on this reply. If you are monitoring an IP Site Connect system then maybe that is handled different than a straight conventional DMR repeater.
 
Joined
Sep 19, 2002
Messages
5,114
Location
Toronto, Ontario
#22
The CRC issue is Motorola RAS changes the header of the voice packet by injecting an encoded stream of bits for RAS transmissions. That makes the header different from RAS to non-RAS transmissions. This changes the CRC check for the packet.
Which is no reason for scanners to fail to deliver audio. It doesn't stop DSD+, so all of the required information is obviously present, despite the mangled CRCs.
 
Joined
Feb 1, 2003
Messages
880
Location
Pequannock, NJ
#24
The system I monitor does not send out short data bursts. The adjacent town which is an IP Site Connect system does.

Not sure why the scanners are slow to decode RAS but one of the primary reasons I bought a new XPR7550e.
 
Joined
Jun 19, 2002
Messages
682
Location
Object-oriented
#26
Comparing it to an XPR7550e with proper RAS code and you can really hear how slow the TRX-2 is to decode.
So a professional grade radio with authorized system access and programming is better at decoding than a hobbyist scanner?

Apples and oranges.

My XL-200 with weekly OTAR'd encryption keys receives our P25 system WAY better than any of my TRX-1 radios...
 
Joined
Feb 1, 2003
Messages
880
Location
Pequannock, NJ
#27
Yes I am, I do have the RAS key loaded on a RX only channel. My point is the TRX-2 is not as good as either the paid version of DSD+ or a XPR7550e.

And again, this is with all receiving radios listening to the frequency and not scanning. I do not know how Whistler is validating an unencrypted voice call over other traffic on the frequency. If we knew how Whistler validates a DMR packet and decodes we could probably explain the differences.

I find the Whistler TRX-2 decoding our P25 phase 1 system does very well, even when stacked up against my APX 8000 or 8500. It just has slight issues with RAS enabled channels.
 
Joined
Nov 13, 2016
Messages
351
Location
England
#30
Whistler probably assume, rightly or wrongly, that it would be illegal to crack the RAS key if that part of RAS is in use. The other part of RAS just restricts the Radio IDs that can transmit through a repeater and is irrelevant to scanner users.
 
Joined
Jul 31, 2005
Messages
91
#33
I have had the following response I’m away from home so not been able to do so yet.

In order to help sort out your DMR issues we need your help.


Thanks for contacting us about your reception issues.
Follow the steps below that will help us determine what the issues are with your system that your monitoring.

1) Turn off and unplug the scanner.
2) Remove SD card and place in card reader
3) Access the SD card in Windows explorer and open the SD card. Open the LOG and REC folders and delete any files inside
4) Replace SD card in scanner
5) Turn on scanner and go to the Main Menu/program menu/Global settings
6) Go down to “Enable Record” option. Check the box
7) Continue to go down the menu list to the “PC/IF CCDump” option . Check it as well as the “to file” option. Save the changes.
8) Exit menu and go to Browse Objects and select the DMR frequencies you are having issues with and check off the “Record” option in each one.
8) IMPORTANT!! Double check that the clock is set to the correct time.
9) Exit menu and start monitoring the system you are having issues with.

After a few good receptions go back into the SD card and send us the files in the LOG and REC folders. You may have to zip
them if too big to email.

If using a DSP+ or other comparison scanning receiver make sure that its system clock is the same setting as the Whistler
Scanner so logs can be compared via time stamps. It will make it much faster for the Software engineer to review.

Plus, any notes on the reception ( also include a time stamp) - did it come in ok, garbled or dead air or didn't unsquelch as
compared to the other receiver. Again; Details and timestamps along with corresponding audio recordings are important.


Sent from my iPhone using Tapatalk
 

benering

Member
Premium Subscriber
Joined
May 8, 2010
Messages
11
#34
I have had the following response I’m away from home so not been able to do so yet.

In order to help sort out your DMR issues we need your help.


Thanks for contacting us about your reception issues.
Follow the steps below that will help us determine what the issues are with your system that your monitoring.

1) Turn off and unplug the scanner.
2) Remove SD card and place in card reader
3) Access the SD card in Windows explorer and open the SD card. Open the LOG and REC folders and delete any files inside
4) Replace SD card in scanner
5) Turn on scanner and go to the Main Menu/program menu/Global settings
6) Go down to “Enable Record” option. Check the box
7) Continue to go down the menu list to the “PC/IF CCDump” option . Check it as well as the “to file” option. Save the changes.
8) Exit menu and go to Browse Objects and select the DMR frequencies you are having issues with and check off the “Record” option in each one.
8) IMPORTANT!! Double check that the clock is set to the correct time.
9) Exit menu and start monitoring the system you are having issues with.

After a few good receptions go back into the SD card and send us the files in the LOG and REC folders. You may have to zip
them if too big to email.

If using a DSP+ or other comparison scanning receiver make sure that its system clock is the same setting as the Whistler
Scanner so logs can be compared via time stamps. It will make it much faster for the Software engineer to review.

Plus, any notes on the reception ( also include a time stamp) - did it come in ok, garbled or dead air or didn't unsquelch as
compared to the other receiver. Again; Details and timestamps along with corresponding audio recordings are important.


Sent from my iPhone using Tapatalk


I had that same response end of last week, and sent the files in this past weekend.
 
Joined
Oct 3, 2014
Messages
28
#38
I have a friend that updated his Uniden for NXDN and saw in the release notes something about RAS improvements.

The problems he had with RAS (same as Whistler) seem to be gone now.

Whistler : Any update coming to correct problems with RAS?
 
Joined
Jul 18, 2014
Messages
8,884
Location
PA
#39
I have a friend that updated his Uniden for NXDN and saw in the release notes something about RAS improvements.

The problems he had with RAS (same as Whistler) seem to be gone now.
I can confirm that monitoring DMR systems with RAS works correctly now on the x36 series.
 
Joined
Feb 1, 2003
Messages
880
Location
Pequannock, NJ
#40
Yes, updated my friend's 536 and RAS decode of conventional DMR repeater is 100% accurate now when compared to a Motorola portable with proper RAS key installed.

Whistler still misses parts or all (short) transmissions. The TRX-2 is sitting here collecting dust. Reason I originally bought it was for DMR RAS receiving.

DO NOT LIKE the fact the scanner memory card gets corrupted if you remove power before the scanner is turned off by power button. Makes install into mobile completely useless if you want the scanner to turn on & off with key.

I will say P25 phase 1 decode is excellent.
 
Status
Not open for further replies.
Top