• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.
  • 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

Some LTR mapping observations

Status
Not open for further replies.
Joined
Jan 6, 2007
Messages
930
Location
N. Colo.
#1
The Wiki and its content is excellent. But there are alternative ways to do mapping. This is puzzle-solving so creativity can be helpful. Here are some things I've learned.

Observations from using a Pro-97 in Colorado. Tedious, but doable.

0. LTR is business radio. Hence the traffic is predominantly during business hours. Trying to map a system during nights and weekends will be less effective.

1. Pro-97 TGID and home LCN reading is useful but is susceptible to noise. Readings taken from a long, strong transmission are valid. Other readings might not be. Noise can cause false TGID display. I've seen brief inaudible blits of LCN 26 or LCN 32 and other nonsense. Logging these TGIDs over many different transmissions will give the picture of what the valid LCN really is. (By logging I mean I'm using a spreadsheet and typing everything I hear so as to be able to correlate things later.)

2. The systems I am finding seem to have the idle strobe enabled. Suspecting this I did a very slow Tune-step search thru the band of interest logging all strobing signals. Band plans have standard channel spacing so stepping to the next valid frequency isn't too hard.
Tune (Funct-Tune - up/down arrow) will find the channel. Using the programmed Search function won't (it seems to be deaf and we're trying to confirm presence of a periodic short burst). Sit on the channel for 5 minutes or so to catch any slow-rate strobes.
Log the frequencies where strobes are found. If possible, listen awhile and log TGIDs and most revealing of all - the CWID (that's the morse code station identifier) if it is sent. The systems I've seen have the CWID on its own TGID which for the Pro-97 reveals the LCN of the channel by its home channel number as well as the LCN reading in the Pro-97's field.

3. With CWID you can look up the FCC license info for the system. (Or not. I found one channel identifying itself with an invalid, not on record, callsign. Confirmed the ID several times. No record. ) Using the FRN license info, you can then get additional frequencies that might be part of the system. Listen to them to detect activity and LCNs you might have missed the first time thru.

3.5 Without CWID you can use the FCC lookup by frequency to get some candidate companies and their alleged transmitter locations.

4. With the spreadsheet you have a frequency, maybe some TGIDs and words, and a possible owner name for the system and an LCN for that channel.

5. After collecting the freq and probable LCN and owner you can sort the spreadsheet by owner and then by LCN to create a trial map of the system.

6. Then test the trial map by listening on each channel (manual) for awhile logging TGIDs. You should expect to see TGIDs that are homed on that channel. What you are really looking for are the other TGIDs that pop up there due to their home channel being busy. These TGIDs will tell you that there are other LCNs in the system. For example, I have a trial map showing LCN 01, 17 and 18 for a system. If TGID 0-04-004 pops up on channel 01 this tells me that I am missing a frequency that belongs to channel 04.

7. In some cases, there may be frequencies that fit into the LCN map but aren't actually part of the system. It is possible to have a single-channel system that IDs itself as having a certain LCN. It seems to me that the only way to sort this out is to listen to that channel and watch for other non-homed TGIDs showing that this channel is indeed part of a system. (It could take awhile to reach a conclusion)

8. Not all channels of a system will have the same callsign. But they will probably have the same owner.

9. Not all freqencies listed on a license are on the same system. Not all frequencies listed are in use. Sometimes frequencies list to different owners and the active/expired info isn't sufficient to resolve the ambiguity.

10. TGID number is not sufficient to prove that it is the same user on the same system. Chances are pretty good, for instance, that every system has a 0-01-001 TGID. You have to listen to the users and perhaps learn voices, names and background noise or signal characteristics (ping-on-transmit, digital data racket, hum, etc) to be sure it's the same users showing up on the different channels.

11. It's likely that certain "styles" help you sort a system. For instance, CWID being on 0x-255 on each channel vs 0x-253. Or that the even LCNs are used but the odd ones aren't.

12. Figuring out who has what TGID is straightforward enough to a certain level. For instance recognizing a car towing service is simple. Identifying WHICH company it is could be impossible just by listening. It might take field work so as to be at a location that's aired in order to put eyes on the radio user to get the company name.

13. Foreign language skills might be required. Many truck drivers hereabouts only speak Spanish. I can track a little of this. One TGID on a particular system has been entirely in Russian. I can recognise their voices and pickup a name here and there but I can't tell what business they are in. (taxi most likely?)


That's all for now. I hope this proves helpful to someone else.
 
Joined
Nov 27, 2004
Messages
137
Location
NW Florida
#2
Try zeromatic OFF on PRO-97 for idle burst searching

NW0U said:
2. The systems I am finding seem to have the idle strobe enabled. Suspecting this I did a very slow Tune-step search thru the band of interest logging all strobing signals. Band plans have standard channel spacing so stepping to the next valid frequency isn't too hard.
Tune (Funct-Tune - up/down arrow) will find the channel. Using the programmed Search function won't (it seems to be deaf and we're trying to confirm presence of a periodic short burst)...
NW0U,

I also use a PRO-97 when tinkering with LTR systems. Have you tried turning off the zeromatic feature when searching for LTR idle bursts? Here's a short thread that describes how to use zeromatic and how using it delays the squelch opening.

http://www.radioreference.com/forums/showthread.php?t=68671

"Just be aware that having ZM on creates a 1-2 second delay before the squelch opens. You'll see the search stop on the "incorrect" freq, pause for 1 to 2 seconds, and then step up to the correct freq. Only then does the squelch open. The only time I keep ZM off is if I'm searching for unknown LTR freqs. The short LTR "data bursts" can be totally missed using ZM."

-Dan
 
Joined
Jan 6, 2007
Messages
930
Location
N. Colo.
#3
Zeromatic

DanHenry said:
NW0U,

I also use a PRO-97 when tinkering with LTR systems. Have you tried turning off the zeromatic feature when searching for LTR idle bursts? Here's a short thread that describes how to use zeromatic and how using it delays the squelch opening.

http://www.radioreference.com/forums/showthread.php?t=68671

"Just be aware that having ZM on creates a 1-2 second delay before the squelch opens. You'll see the search stop on the "incorrect" freq, pause for 1 to 2 seconds, and then step up to the correct freq. Only then does the squelch open. The only time I keep ZM off is if I'm searching for unknown LTR freqs. The short LTR "data bursts" can be totally missed using ZM."

-Dan
Good info. I was unaware of any effects that ZM might have. It still seems to me that having a high-speed sweep thru the band is more likely than not to miss the strobe.
Once I figured out the band plan I could even type the expected frequencies into the spreadsheet before I stepped to them.

When using sweep with ZM off, how do you know when you've covered the band? (i.e. how do you know you can stop searching?)
 
Joined
Nov 27, 2004
Messages
137
Location
NW Florida
#4
NW0U said:
When using sweep with ZM off, how do you know when you've covered the band? (i.e. how do you know you can stop searching?)
There's no exact answer to that one. A quick test here doing a program search from 856.0 - 856.1 with zeromatic off would conistently pick up every idle burst. When you increase the search range to a few hundred Khz you start to miss a few so I would let it run for a couple of minutes.

-Dan
 

Airdorn

Member
Premium Subscriber
Joined
Mar 9, 2008
Messages
428
#6
BC_Scan said:
NWOU, pm sent based on my observations .
Hey, could you share those observations with us all? I'm just now getting into piecing-together a couple of very chaotic LTR systems around here and need all the info I can get. :)

I've resorted to loitering around job sites and vehicles of 'suspect' companies, hoping to snag a juicy freq. or three with this little Radio Shack PRO-84 and its SignalStalker function.
 
Joined
Jan 6, 2007
Messages
930
Location
N. Colo.
#7
Tips

Airdorn said:
Hey, could you share those observations with us all? I'm just now getting into piecing-together a couple of very chaotic LTR systems around here and need all the info I can get. :)

I've resorted to loitering around job sites and vehicles of 'suspect' companies, hoping to snag a juicy freq. or three with this little Radio Shack PRO-84 and its SignalStalker function.
I asked BCscan the same thing but he hasn't chosen to post.

Since LTR systems are input/output repeater based, hanging around jobsites might not get what you want unless you can figure out the offsets between input and outputs. of course at the jobsite you can get the company name as opposed to the generic "concrete truck" that I can submit.

Since I started this particular thread I've submitted 2 simple systems and one complex one. The complex systems here seem to have at least 3 different licenses involved though the same company owns them all.
My best hint has been to wait patiently to hear the morse code (cw) identifier and then look up the licensee and then see what else they own in the same frequency range.
 
Joined
May 29, 2011
Messages
1,466
Location
York county Me.
#8
My 1st ltr mapping was luck. I programmed an ltr system into a friends scanner and got it right.WITHOUT the book. So now, I use the function on the pro 106--H.R move. It is the cats claw. No waiting for nadda. After you get your 1 st entity, you EDIT the system just to see where the freqs end up-numerically.
 

tommyscan

Member
Premium Subscriber
Joined
May 28, 2008
Messages
342
Location
seaford new york
#9
Ltr systems are quite frustrating to monitor. I know part of the fun is to discover new channels and talkgroups but in my area there are soo many cross over channel usage trying to figure out what you are monitoring is almost out of the question. Sometimes you just want a confirmation and the pleasure of monitoring without the guess work!!
 
Joined
May 29, 2011
Messages
1,466
Location
York county Me.
#10
Depends on your equipment. I think.. I have uniden 15x that soes not catch an ltr transmission as fast as a pro106 or 197.tested many times over. However, on the 800 nhz band where entities are few and far between, they both catch the ltr excellently..But, a busy uhf trunk-my $$ goes with pro's-106/197
 
Joined
Jul 27, 2004
Messages
16
#11
Depends on your equipment. I think.. I have uniden 15x that soes not catch an ltr transmission as fast as a pro106 or 197.tested many times over. However, on the 800 nhz band where entities are few and far between, they both catch the ltr excellently..But, a busy uhf trunk-my $$ goes with pro's-106/197
I am also trying to monitor an unknown LTR system. From my observation, the repeater number keeps changing now and then making monitoring it very frustrating. The frequencies run from 851 to 860 Mhz with 25Khz spacing. I am thinking to program all the frequencies into my Pro 106 and let the auto move feature does the rest. But I just don't know how to do it. Any suggestions?
 
Status
Not open for further replies.
Top