Scanning ASTRO25 systems in talkgroup scan

Post by Pj » Thu Nov 20, 2008 8:21 am

Does anyone know if this actually works? If your sitting on a conventional channel, is there anyway to hear talkgroup that is on an ASTRO25 system?

I know Moto is all about affilating to the system, but why be able to include it in a scan list if you can never hear it?

Presently using a XTL5k with FW/CPS 12 with proper flashcode.

dxon2m · Post by **dxon2m** » Thu Nov 20, 2008 10:02 am

If your sitting on a conventional channel, is there anyway to hear talkgroup that is on an ASTRO25 system?

Not too sure if I understand this correctly, but I have a XTS2500 monitoring a ASTRO25 system with the voice frequencies all programmed in. I set all channels to F7E (NAC monitor), created a scanlist with all the voice channels and set to automatic scan with a hang time of 0. I was able to monitor a ASTRO25 system without affilation. Granted, I was techniclly monitoring P25 conventional channels and the system has only ONE talkgroup.

immelmen28 · Post by **immelmen28** » Thu Nov 20, 2008 1:39 pm

Pj wrote:Does anyone know if this actually works? If your sitting on a conventional channel, is there anyway to hear talkgroup that is on an ASTRO25 system?

I know Moto is all about affilating to the system, but why be able to include it in a scan list if you can never hear it?

Presently using a XTL5k with FW/CPS 12 with proper flashcode.

It will work. The radio will not affiliate with the system when only scanning a talkgroup when the selected channel is conventional or a different TRS, rather just check for activity on the talkgroup and it will pass the audio with out affiliating. My guess, the software has to allow it otherwise scanning multiple TRS's would take an eternity if you had to wait for affiliation on every scan list member. just never directly select the talkgroup...at least not on 800 systems, OBT is a different story.

tvsjr · Post by **tvsjr** » Thu Nov 20, 2008 1:45 pm

immelmen28 wrote:It will work. The radio will not affiliate with the system when only scanning a talkgroup when the selected channel is conventional or a different TRS, rather just check for activity on the talkgroup and it will pass the audio with out affiliating. My guess, the software has to allow it otherwise scanning multiple TRS's would take an eternity if you had to wait for affiliation on every scan list member. just never directly select the talkgroup...at least not on 800 systems, OBT is a different story.

Presumably an OBT system will attempt to affiliate as well, except you can control the input. What happens once it fails in affiliation? Does it pass audio if it can still hear the system but was unsuccessful at affiliation?

caprice96 · Post by **caprice96** » Thu Nov 20, 2008 1:47 pm

Post by Pj » Thu Nov 20, 2008 1:59 pm

Ok, lets try this again

Radio has an ASTRO25 system PROPERLY programmed into the radio.

I want to include a specific talkgroup in the scanlist (set as talkgroup scanning which allows conventional and trunked systems in one list).

The radio will normally sit on a conventional channel.

This works just fine on 3600 systems.

The 9600 system will not unmute.

I am pretty sure that this is delibrate from Motorola, as if you have TX inhibit or another option enabled on in the advanced tab for ignition switching, the help file states it will not unmute radio traffic. However the help file states that Smartnet/SZ system are not affected, which they are not (they unmute just fine with or without power to the ign wire).

However, I can't see why, since you can place ASTRO25 talkgroups in the talkgroup list, and not have them work. This is Moto afterall, so it wouldn't surprise me for this to never work.

mike m · Post by **mike m** » Fri Nov 21, 2008 10:20 am

it works just fine on astro25 9600 trunking systems also.

You don't need to set anything to NAC F7E or any nonsense like that just make sure yoiur conv personalities are set to non astro as these will be calling your astro talkgroups.

I'm Sitting here right now monitoring a 700/800 MHz 9600 baud P25 system on an xts5000 that is 75 miles south of me with the power tracking set to zero for everything, tx inhibit on and a tee connecting my antenna to my R2670 and never once has the radio affiliated.

A Very important step is to Make sure that the conventional channels which call your trunking scan list are all set for non astro receive mode other wise the radio will not unsquelch.

Also make sure that the conventional personalities which call your trunking scan lists have autoscan enabled and that the trunking personality which you are trying to scan has the same scan list as the conv personality which calls it and that auto scan is enabled it as well.

basicsally the steps are first
Set your conv menu items as follows> zone mute tx inhibit, it doesn't really matter as long as you can get to your zones and enable tx inhibit. make sure to set squelch accordingly in the conv personality which will call your trunking scan list.

You don't really need anything in the trunking menu but I usually throw something there anyway, not sure why I did it but I have zone and channel in mine and I find it works just fine.

#1. make up your astro25 9600 trunking system, I know someone will jump in and correct me that it;'s biphase 4800,
put the CC's for only one site in to keep things simple. And don't turn on smartzone, you can play with this later but for now don't complicate matters.

The only fields you need to open in the trunk system are general, 700 800 astro25 control channels and digital, leave all others at the cps defaults.

I listen to single sites only and it works very well for me. I find that setting modulation to QPSK works fine in the digital selection.

#2 make up your trunking pers with the same system as in step 1 and assign this pers to scan list 1 and enable autoscan.
put as many talkgroups in as you want in this trunk pers. The Only fields you need to open in trunk personality are general, talkgroups and scan leave all others at the cps default.

Note: if later on you want to make up another trunk pers which for instance is a 3600 digital one then make sure you have the tx voice signal type field in the talkgroup selectiion set to digital. Even though the radio isn't going to tx it needs this field set accordingly for proper receive.

#3. make up a conventional pers, lets say pers 1, set the unmute time to zero and the receive to non astro, assign scan list 1 to this personality also and enable autoscan.
NOTE: Don't set any of the conventional channels which will call your astro trunk sytem to astro mode other wise you will hear nada, simply set all conv channels to non astro and it will work fine.

Another thing I forgot. I usually use the CPS default RX frequency fo my conv channels as I have never heard anything on 851.0625 but if you get interference then you will have to change the conv rx frequency to something with no activity.

I use the CPS default of unmute/ or mute rule and this works fine for me. Don't do anything else in the conv personalities.
The only fields in the conv personality you need to touch are RX option and scan, use the cps default for all others.

You'll have some errors in scan list #1 at this point until things are all tied together so ignore them for now.

#4 in the zone field for zone 1 assign the first 16 channels to conventional pers 1, assign channel 17 to trunking personality 1 and select whatever talkgroup you want to listen to, you can also add additional talkgroups for this same trunk pers after channel 17 if you want with the same trunking pers but different talkgroups.

#5 in scan list #1 turn on talkgroup scan but don't assign any priorities. Set the trunking system to r record #1 and then go to the channel field of scan list 1 and assign the first channel as zone 1 channel 17, assign any other talkgroups you want to listen to after the first channel in this scan list for instance zone 1 channel 18 for another talkgroup of the same trunk pers.

Also I do not have any conv channels in my talkgroup scan list, only P25 trunking.

Program the radio, remove the antenna and turn the radio on and in the menu select tx inhibit.

Attach the antenna and turn the radio on and when it comes up on any channel in zone 1 it will scan the system without user intervention and no affiliation.

cbus · Post by **cbus** » Sat Nov 22, 2008 9:23 am

What a ripper of a post Mike!

Champion!

mike m · Post by **mike m** » Sat Nov 22, 2008 1:13 pm

I have received some PM's about adding 700 MHz control channels so here goes.

adding 700 control channels.

You can either overwrite the default 800 channel ID info or turn on a 2nd row of 700 control channle ID, either way here is the info.

Go into your trunking system that you need to change or add 700 control channels and open up ASTRO 25 channel ID

You should have a default setting for 800 Mhz already with a Minus tx offset sign, transmit offset of 45.000 MHz and a base frequency of 851.00625.

Do the following:
1. on the column that says 'identifier enable' click on and enable row 2 and enter the following if you need 800 and 700 control channels or if you only need 700 control channels then simply overwrite row 1 data with the following :

step A. Leave channel bandwidth at 12.5 KHz,
step B: On the column for transmit offset sign click on the selection and use the up/down arrow selection to select +
step C: On the column for 'transmit offset [MHz] enter 30.00000
step D: On the column for channel spacing leave this at 6.25 KHz
step E: On the column for base frequency enter 762.00625

Now go to 700_800_astro25 control channels and for the column that says channel ID number pick the selection that matches your 700 MHz one that you entered in the ASTRO25 channel ID above.

If you left the 800 default channel ID band plan in and made a 2nd channel ID field then your choice will be 2, if you overwrote the first channel ID info 800 field with 700 MHz info then your channel ID number will be 1.

Also, You can mix in 700MHz and regular 800 control channels if you change the channel ID number to the left of the respective control channel accordingly.

Once you get the correct channel ID number entered in the 700 800 astro25 control channel menu just enter in your 700 control channels and save the codeplug and then program your radio.

mike m · Post by **mike m** » Tue Nov 25, 2008 7:28 pm

Any feedback on this method ?

caprice96 · Post by **caprice96** » Wed Nov 26, 2008 11:19 am

All I can say is bravo and works like a charm. A++++ Mike.

immelmen28 · Post by **immelmen28** » Wed Nov 26, 2008 11:57 am

tvsjr wrote:
Presumably an OBT system will attempt to affiliate as well, except you can control the input. What happens once it fails in affiliation? Does it pass audio if it can still hear the system but was unsuccessful at affiliation?

Has anyone experimented with this on a VHF/UHF OBT 9600 system set up this way to see if it will unmute/pass audio with incorrect input freqs preventing affiliation?

mike m · Post by **mike m** » Wed Nov 26, 2008 1:37 pm

I don't have any XTS's to test out this week on a UHF system.

I'm stuck with a Uniden 396 scanner that just doesn't have the sensitivity that the XTS does.

I had to return the 700/800 XTS5K back to the owner who brought it for a 2 day visit.

I can probably get my friend who works at a fed 3 letter agency to bring a UHF low XTS for his next visit and I'll give it a try if nobody else does.

Mike

Post by Pj » Wed Nov 26, 2008 3:32 pm

So far, no on a VHF A25 system. You can control affailation via ign control on the Xtl. The radio will show the signal strengh, RSSI and site, but no audio (so far). Enabiling TX via the ign results in the same if dummy freqs are used.

mike m · Post by **mike m** » Fri Nov 28, 2008 12:57 pm

Bummer,

No VHF systems on this end and no radios for a couple of months to play with.

Did you double check to make sure that the conventional pers calling the VHF A25 system is set for non-astro mode and also that no rx PL is turned on ? I made this mistake a couple of years ago on a 3600 800 Astro system and it drove me nuts for the entire weekend until I got to my CPS PC and found the error.

Mike

Post by Pj » Fri Nov 28, 2008 5:52 pm

This is on an XTL with a properly programmed astro25 system, sitting on a local conventional channel, but with talkgroups in the scan list (talkgroup scan).

mike m · Post by **mike m** » Sat Nov 29, 2008 6:00 pm

OK,
Didn't see that yours is an XTL mobile.

All I had to play with were XTS5K's

mike m · Post by **mike m** » Mon Dec 15, 2008 6:05 am

Has anyone been able to get a 700 system to work ?

I think I have typo in the base frequency for the 700 MEG channel ID.

I think it should be 764.00625 meg not 762.00625 meg.

Ignore this I just got to work and checked the settings on my R2670 and 762.00625 MHz is correct for the base frequency.

The problem was that a friends radio needs to be flashed to a higher level.

We were seeing the radio display talkgroups on a 700 meg system but no audio was coming out on clear talkgroups yesterday and it turned out that he had very early firmware in his radio.

Mopar078 · Post by **Mopar078** » Tue Feb 10, 2009 11:50 am

762.00625 should be correct, thats what they're using on our 700mhz system in my area. So your saying if I program a radio the normal way for a 9600 trs and the radio doesn't affiliate it wont unmute but if I program it like your above post then it should unmute? I haven't had a chance to try this yet but I will let you know if I get it to work.

mike m wrote:Has anyone been able to get a 700 system to work ?

I think I have typo in the base frequency for the 700 MEG channel ID.

I think it should be 764.00625 meg not 762.00625 meg.

Ignore this I just got to work and checked the settings on my R2670 and 762.00625 MHz is correct for the base frequency.

The problem was that a friends radio needs to be flashed to a higher level.

We were seeing the radio display talkgroups on a 700 meg system but no audio was coming out on clear talkgroups yesterday and it turned out that he had very early firmware in his radio.

mike m · Post by **mike m** » Tue Feb 10, 2009 1:00 pm

It doesn't seem to work on a 700MHz system, it will only unmute on 800 control channels.

I tried my friends radio this past weekend and it didn't work on a 700 MHz system.

Earlier I said it had worked but we found out that he was scanning a dual 700/800 system and it was un-muting fine to traffic on the 800 control channels, which is a site 25 miles away from the 700 site, as for the 700MHz site, well the radio showed the correct talkgroups but it never unmuted to audio.

I was going to try entering in the 700 MHz voice channels in a conventional zone and set the NAC for F7E on this system but we ran out of time.

Mike

dxon2m · Post by **dxon2m** » Tue Feb 10, 2009 1:47 pm

I tried a similar method Mike, but instead of creating my own trunking system and personality. I had created one conventional personality (Astro receive only, selective squelch) and assigned my control channel and voice channels using that personality.

I created a scanlist with all the control and voice channels with autoscan enabled. I was able to monitor specific talkgroup that I want using the TGRP menu key. Under my Astro systems, I would have to create a list of talkgroup IDs which I intend to monitor in order to be selectable in the TGRP menu. So far my radio will happily filter out the other encrypted stuff and only unmute on the talkgroup I selected.

So far I monitor that system using Unitrunker and I haven't seen my radio ID popping up. I wonder if I'm still on the safe zone..?

mike m · Post by **mike m** » Tue Feb 10, 2009 3:47 pm

dxon2m,

That's a great way to monitor, the next time I'm visiting my friend with the XTS5000 I'm going to try with your conventional method in one zone and mine in an adjacent zone.

This way I can scan the entire 700 MHz system listening to all VC's with digital CSQ enabled in one zone.

If I find an interesting talkgroup then I can switch over to the zone with your method enabled and zero in on a particular talkgroup.

For now I'm stuck using a Uniden digital scanner that doesn't have the sensitivity or dynamic range that the commercial radios have.

Your method will actually work much better since some of the talkgroups are encrypted in this 700 MHz system.

Mike

Mopar078 · Post by **Mopar078** » Tue Feb 10, 2009 6:00 pm

I guess I don't get it. Are you only monitoring one talkgroup at a time?

dxon2m wrote:I tried a similar method Mike, but instead of creating my own trunking system and personality. I had created one conventional personality (Astro receive only, selective squelch) and assigned my control channel and voice channels using that personality.

I created a scanlist with all the control and voice channels with autoscan enabled. I was able to monitor specific talkgroup that I want using the TGRP menu key. Under my Astro systems, I would have to create a list of talkgroup IDs which I intend to monitor in order to be selectable in the TGRP menu. So far my radio will happily filter out the other encrypted stuff and only unmute on the talkgroup I selected.

So far I monitor that system using Unitrunker and I haven't seen my radio ID popping up. I wonder if I'm still on the safe zone..?

dxon2m · Post by **dxon2m** » Tue Feb 10, 2009 6:28 pm

Correct, I am only monitoring one talkgroup at a time. I tried this on a system that doesn't have a lot of channels and talkgroup active. I don't have a statewide system that I can try on so I can't speak for it.

Mike is right about the sensitivity of commercial radio, my XTS2500 will pick up loud and clear (and actually sounds pleasant to my ear) while my BCD396 won't even pick up the control channel.

Post by **laramiecountyCERT** » Tue Apr 07, 2009 10:47 pm

So was anyone able to see if they could get the scan to work on a VHF system? Still new at programming XTS radios for the moment and added in a XTS5000 to the mix of radios now. I take it you can set the radio for conventional and scan talkgroups for each site with no problem? I read the post and its seems like you can get the TXS to scan with the control channel and the talkgroups programmed in or am I missing something? I am not used to programming for trunked systems as for the longest time we have had nothing but conventional up here in Wyoming so the trunking is new to me. Just trying to understand how the scanning of the trunking happens in the XTS radios.
Thanks

Mopar078 · Post by **Mopar078** » Wed Apr 08, 2009 10:23 am

I got it to work on a 700mhz 9600 Simulcast System. This is what I had to do just to listen to 10 talkgroups. I put all the trunking channels into conventional personalities and set all of them to scan list 1, then I setup everything in the trunking system field and added 10 personalities then selected scan list 1 and checked automatic scan because that is all I can fit in the scan list when set to talkgroup scan. After I made sure TX inhibit was enabled I tried sitting on a talkgroup and it wouldn't decode because I wasn't affiliating but when you sit on a conventional channel it will decode audio just fine and show you which one of the ten talkgroups that is talking with no issues. The only problem with this is I had to assign all the conventional channels to different scan list for every ten talkgroups I added per zone. I really would not of thought this would have worked until I tried it.

Post by **laramiecountyCERT** » Thu Apr 09, 2009 8:40 am

OK I got a little lost in that post, but let me see if I got this straight. Program your control channel in conventional and your talk groups in the trunking system for scanning? I don't have a lot of talkgroups as our system is going to be just a few agencies in the local area. I am using a XTS5000 for this project. Right now we only have DOT and WHP on it but will be adding more as the rest of the system comes on line. So each site has to be programmed in as a conventional but the talkgroups have to be in the trunking system correct?

Thanks

Mopar078 · Post by **Mopar078** » Thu Apr 09, 2009 10:27 am

laramiecountyCERT wrote:OK I got a little lost in that post, but let me see if I got this straight. Program your control channel in conventional and your talk groups in the trunking system for scanning? I don't have a lot of talkgroups as our system is going to be just a few agencies in the local area. I am using a XTS5000 for this project. Right now we only have DOT and WHP on it but will be adding more as the rest of the system comes on line. So each site has to be programmed in as a conventional but the talkgroups have to be in the trunking system correct?

Thanks

Sorry if it was confusing, it was hard for me to figure out. For the site your trying to monitor program all voice and control channels in conventional mode and put them all in the same scan list, if its a digital system use nac F7E. Then make sure under trunking systems you have all the fields correctly entered including control channels for the site your trying to monitor. Under scan list make sure you selected talkgroup scan and select up to 10 talkgroups and if you select scan list 1 make sure under conventional personalities that all voice and control channels you put there are all set to scan list 1 and check the box that says automatic scan with unmute time set to zero. I put all talkgroups, voice, and control channels all in one zone and that is the only way I could get audio is to sit on a voice or control channel and not a talkgroup channel. I had mine set up like this it worked fine as long as I was on channel 1,2,3, or 4.

Zone 1
1. Voice Channel
2. Voice Channel
3. Voice Channel
4. Control Channel
5. VDOT 1
6. VDOT 2
7. VDOT 3
8. VDOT 4
9. VDOT 5

Mopar078 · Post by **Mopar078** » Thu Apr 09, 2009 10:29 am

laramiecountyCERT wrote:OK I got a little lost in that post, but let me see if I got this straight. Program your control channel in conventional and your talk groups in the trunking system for scanning? I don't have a lot of talkgroups as our system is going to be just a few agencies in the local area. I am using a XTS5000 for this project. Right now we only have DOT and WHP on it but will be adding more as the rest of the system comes on line. So each site has to be programmed in as a conventional but the talkgroups have to be in the trunking system correct?

Thanks

Sorry if it was confusing, it was hard for me to figure out. For the site your trying to monitor program all voice and control channels in conventional mode and put them all in the same scan list, if its a digital system use nac F7E. Then make sure under trunking systems you have all the fields correctly entered including control channels for the site your trying to monitor. Under scan list make sure you selected talkgroup scan and select up to 10 talkgroups and if you select scan list 1 make sure under conventional personalities that all voice and control channels you put there are all set to scan list 1 and check the box that says automatic scan with unmute time set to zero. I put all talkgroups, voice, and control channels all in one zone and that is the only way I could get audio is to sit on a voice or control channel and not a talkgroup channel. I had mine set up like this it worked fine as long as I was on channel 1,2,3, or 4.

Zone 1
1. Voice Channel
2. Voice Channel
3. Voice Channel
4. Control Channel
5. VDOT 1
6. VDOT 2
7. VDOT 3
8. VDOT 4
9. VDOT 5

Post by **laramiecountyCERT** » Tue May 05, 2009 11:44 am

Ok so what are the VDOT Channels?

Mopar078 · Post by **Mopar078** » Tue May 05, 2009 2:35 pm

laramiecountyCERT wrote:Ok so what are the VDOT Channels?

I just made up a channel name but they will be your talkgroups.

Post by **laramiecountyCERT** » Wed May 27, 2009 2:21 am

Question on this method, are you using just the main CC or are you adding in alternates? I have main CC added in but was curious as to if the alternate needed to be added in as well as I am assuming that the alternate CC is backup. Another question is can you have multiple CC for different sites entered into the same scan list? I have two towers that I would like to monitor that are in town. Would that work to be able to do this?
Thanks

dxon2m · Post by **dxon2m** » Thu Jun 11, 2009 4:39 pm

Has anyone tried monitoring system with more than 16 voice channels? I need to get it scanning more than 16 channels but CPS won't allow me to do so.

Thanks

Elroy Jetson · Post by **Elroy Jetson** » Sun Jun 28, 2009 7:42 pm

I'm attempting to scan a UHF low .gov trunking Astro system in CONVENTIONAL Astro mode. Since the system has a very low traffic level and
uses transmission trunking, it'll work as well as if I had an authorized trunking radio on the system, I think. Almost never will two conversations
be going on at once on a single site.

This worked great when I had my XTS5000 but I sold that for a fat profit. Now I'm trying it with an ASIII with suitable features and latest firmware
and it's not working right. I get garbled audio 9 times out of 10. I don't think the system has changed over to full P25, either, and I don't think that
would matter anyway.

Any ideas of why it might be doing what I'm noticing?

Elroy

MTS2000des · Post by **MTS2000des** » Sun Jun 28, 2009 10:39 pm

what is the firmware and DSP? lots of ver HOST/DSP 5 and 6 Astro Saber/XTS3000 on Brokenstolenradios.com and there is a huge difference in performance on IMBE between old DSP and latest DSP.

I use a UHF XTS5000 with R12.01 and it excels and monitoring an Astro 25 UHF system conventionally (which is nice, as all channels are set to RX only so no chance of RF ever coming out on any unauthorized frequencies!) on a similar system in this manner.

Elroy Jetson · Post by **Elroy Jetson** » Mon Jun 29, 2009 5:00 am

Host R07.71.06 and DSP I08.03.05, very current.

Today the radio's picking up voices a lot better than last night. I have no idea why. I haven't changed the programming.

I'll be putting the radio through alignment today anyway. Maybe that'll help.

Elroy

MTS2000des · Post by **MTS2000des** » Mon Jun 29, 2009 7:36 am

just by chance is it a simulcast system? if so make sure the modulation is set to CQPSK instead of C4FM. Makes a huge difference if the system you are listening to is simulcast P25 and uses CQPSK.

Elroy Jetson · Post by **Elroy Jetson** » Mon Jun 29, 2009 8:14 am

It is a five site system, SmartZone, but I'm not sure if it's simulcast or not.

It's the KSC/CCAFS UHF low range system that's in the database.

Out of curiosity, what is the standard tx/rx offset on UHF lowband trunking systems, anyway?

Elroy

Twisted_Pear · Post by **Twisted_Pear** » Tue Jun 30, 2009 12:03 pm

Elroy Jetson wrote:Out of curiosity, what is the standard tx/rx offset on UHF lowband trunking systems, anyway?

Typically +9MHz. Goes for conventional too.

Elroy Jetson · Post by **Elroy Jetson** » Tue Jun 30, 2009 3:44 pm

Cool, thanks for the info. I'm trying to learn how OBT Astro systems are put together. It gets kind of different when you've got both trunked talkgroup and digital talkgroup options BOTH to deal with. I'd imagine it can become one big hairy deal to figure out.

I understand conventional Astro systems with digital talkgroups, and I understand Moto trunking up to and including SmartZone systems, but when you put
digital talkgroups into the picture, it's a new game.

Elroy

Elroy Jetson · Post by **Elroy Jetson** » Sun Jul 05, 2009 4:52 pm

I did figure out the voice problem I was experiencing. It would appear that certain users are using ADP while others are not. My own experiments with ADP-enabled and non-ADP-enabled radios talking together (with the ADP-enabled radio in ADP mode) give identical results to what I'm hearing.

I can't be sure they're using ADP but they are using some form of encryption. But only certain users are doing it.

Elroy

MotoFAN · Post by **MotoFAN** » Sun Nov 15, 2009 1:49 pm

Hi all!

I am listening Astro25 Trunking System (9600 bps) by using XTS3000. Radio does not supports ASTRO 25 9600 Baud Trunking, therefore I have programmed voice channels as Conventional personalities with Astro voice and suitable Network ID. And all works fine! I am able to listen all digital conversations in Trunking System!

But problem is that I do not want to listen all talkgroups. I want to listen only preferred groups.

Any way to set needed TGID number somewhere in CPS?

dxon2m · Post by **dxon2m** » Sun Nov 15, 2009 6:39 pm

You can setup the talkgroups you want to monitor in the talkgroup list under Astro systems, than enable TGRP option in the radio menu to allow access to the talkgroup list through the radio's keypad.

Have a look at this thread, it pretty much details the steps and limitations of this neat feature!
http://batboard.batlabs.com/viewtopic.php?f=4&t=81662

Post by **alex** » Sun Nov 15, 2009 8:04 pm

Merged threads.

MotoFAN · Post by **MotoFAN** » Mon Nov 16, 2009 1:20 pm

Thanks to all.

Questions:

1. Anybody done it with OBT and Astro radio (XTS3000/Astro Saber/Astro Spectra)?
2. How to convert TG numbers from Uniden decimal format to suitable for Motorola CPS format? Or no conversation required?

dxon2m · Post by **dxon2m** » Mon Nov 16, 2009 7:40 pm

MotoFAN wrote:Thanks to all.

Questions:

1. Anybody done it with OBT and Astro radio (XTS3000/Astro Saber/Astro Spectra)?
2. How to convert TG numbers from Uniden decimal format to suitable for Motorola CPS format? Or no conversation required?

Ans 1. The three systems that I monitor using the method described above are all in 380MHz, UHF-L and UHF-T. They all work fine

Ans 2. If you are using the method described above (talkgroup list), you don't need to convert them to Moto Hex, just use the decimal number.

Post by Pj » Mon Nov 16, 2009 8:15 pm

Anyone who has this working care to make a nice cheatsheet and I'll make it a sticky

mancow · Post by **mancow** » Mon Nov 16, 2009 9:47 pm

+1 on that suggestion. It's kind of a

trying to figure it out from all the info in the thread.

Pj wrote:Anyone who has this working care to make a nice cheatsheet and I'll make it a sticky

515 · Post by **515** » Tue Nov 17, 2009 8:36 am

I'll take a stab at it...

It is possible to listen to a specific talkgroup on trunked system's voice channels (P25 audio) with a Motorola P25 radio flashed for conventional only. This is possible since the talkgroup info is encoded into the P25 voice transmissions.

Basically what you want to do is set up a conventional scan list consisting of conventional channels for each of the system's voice channel frequencies. Each personality is programmed with the "RX Unmute Rule" set to "Selective Squelch", which requires both correct NAC and talkgroup values for the radio to unmute.

This method does have some limitations... It works best on systems that aren't very busy, as each "sample" of a channel takes a few hundred milliseconds, so if you're scanning past a bunch of undesired TG's, you're likely to miss some desired activity. But on the plus side, there's no risk of affiliating or transmitting on the system if each channel is programmed to RX-only. And the Motorola radios will typically stay muted on encrypted transmissions, unlike most scanners.

Listening to more than one TG can be difficult, unless it's a small (like 5 frequency or less) system that's not busy. To do this, you'd have to program each freq/TG combination, so listening to 3 TG's on a 5 frequency system would take 15 conventional channels.

Depending on what Motorola radio you're using, you'll probably need to know the NAC or Network ID in use on the voice channels. For 3600 bps systems, it's usually the last two digits of the system ID followed by one other number. So if the system ID was 3E47, the NAC would likely be 470, 471, 472, 473, 474, 475. For 9600 bps CC systems, the NAC is often very similar to the three digit system ID, so if the system ID was 3C4, I'd try NAC's of 3C4, 3C1, 3C2, 3C3, 3C5, ect. The newer P25 scanners will read out the NAC in use on the voice channels, and you can also try the kNACk application from unitrunker.com, as well. Be aware the NAC's can differ between different sites on the same system.

Some newer Motorola radios might allow you to use the wildcard NAC of F7E, but I wouldn't count on this working for the older XTS3000/Astro Saber series. F7E isn't a wildcard value on those older radios. So if there's any way you can figure out the actual NAC in use on the voice channels, that's the way to go.

So once you have the NAC and TG info, you can program the radio:

First, set up an Astro Talkgroup list, which is under Conventional->ASTRO Systems. Under the "Talkgroup Table" tab, enter a decimal value for each TG you want to listen to.

For 9600 bps control channel systems, you should be able to use the decimal TG value straight from a "scanner list".

For 3600 bps control channel systems, to convert from the "scanner" decimal talkgroup format, first convert it to hex, then remove the least significant digit (usually a zero), then convert it back to decimal.

So if you have a talkgroup list intended for a scanner (from radioreference.com or whatever):

Say you want to listen to TG 4400 from that list:
First convert it to hex: 1130
Then remove the least significant digit: 113
Then convert it back to decimal: 275
275 is the conventional talkgroup value needed in an Astro radio.

If you don't know the TG's, it is possible to have the radio display them as they are received. You can do this by going into Radio Configuration->Display&Menu, "Advanced" tab, and checking the box for "Talkgroup Display on Recieve". You'll need to have the personality's "RX Unumute" rule set to "Normal Squelch" to hear everything, though. The radio will display the TG in decimal format.

Once the TG list is complete, then create/edit a conventional personality and Zone Channel assignment for each system voice channel and desired TG. Program each frequency in (including the control channel, in case it rotates to another channel) and name it according to the desired TG that you want to listen to. You could name each channel identically with the TG name, but it may not hurt to squeeze a channel number in there too.

Under the Conventional Personality screen, under the "ASTRO Talkgroup Options" tab, make sure "Talkgroup" is checked, and choose your TG from the proper list. Then click on the "ASTRO" tab, set the RX Network ID to the correct value, and change the "Rx Unmute Rule" to "Selective Squelch". If the scan list that you want to use is already created, set the "Scan List Selection" to the proper value under the "Scan" tab.

Finally, set up your scan list under Scan->Scan List. "Scan Type" should be "Conventional", and set the list up to include all of the active voice channels, but don't include the control channel, as this will slow the scanning down.

Unfortunately, this method doesn't work very well with many non-Motorola P25 radios. This is because the TG value doesn't appear in every frame on a trunked voice transmission. In a typical conventional P25 voice transmission, the TG value occurs in the header and once per 360ms superframe. On most Motorola trunked systems, it seems only every other superframe contains the TG info. This doesn't bother the Motorola radios, but most other radios act funny with this. Some always mute on the superframes that don't contain a TG value, while others always unmute on those superframes that don't contain a TG value (you get audio that cuts in and out). The Motorola radios basically continue whatever mute/unmute state they were in before they encounter a frame without TG info.

I put this together kind of quickly, so I hope it doesn't have any major errors. I'll try and answer any questions, though.

mancow · Post by **mancow** » Tue Nov 17, 2009 11:14 am

Excellent! Thank you.