Another LTR System

[IdleMonitor]

Ok, So, with this one http://www.radioreference.com/modules.php?name=TRSDB&sid=4297 Is it even worth putting into the radio.

On another radio I had, I had put this frequency in and all I ever heard was blips, but that was about it. No voice activity.

 

[EricCottrell]

Hello,

You will only hear voice on the site if there is an user in the area.

I looked at the site information in the RRDB and also did a search in the TAFL of Action RF frequencies and suspect that this is part of a multiple site LTR system. Action RF has several sites that only use one frequency which tells me they are low usage fringe area or fill-in sites.

The description of the rapid keyups does not say LTR-Net or ESAS to me but rather a Passport LTR system. Passport also supports Regular LTR. If you hear keyups, with no voice or audible data, every 1 to 4 seconds then it is likely Passport.

Searching the TAFL I noticed some additional licensed frequencies for Action RF not listed in the RRDB for this system http://www.radioreference.com/modules.php?name=TRSDB&sid=4210
The additonal frequencies for the Ottawa Place De Ville Twr C site are
853.387500 853.637500 853.887500 854.137500 854.387500 854.812500 860.112500 860.612500 860.737500 861.112500 861.362500 861.612500
I suspect that the additional frequencies with the ones listed in the RRDB are part of a Passport LTR system. The site has mixed Passport and Regular LTR with the additional frequencies used for Passport. It is also possible that they are two separate systems with the additional frequencies possibly Passport.

The other unknown Action RF sites listed in the TAFL are
Ottawa 1000 Castlehill
858.087500 858.337500 858.587500 858.837500 859.087500

Nepean
855.837500 861.412500 861.662500 861.912500 862.162500 862.412500

Brockville
862.537500 863.037500

If any of these sites are within monitoring range you could see if there is LTR activity or rapid keyups on the frequencies.

73 Eric

 

[IdleMonitor]

Well, I've put it in as an LTR system in the 246T.

Now I guess all I can do is change the LCN every day or something to see if there's anything that comes up.

I can see how it could be used as a multiple site frequency. I've read on there website how they boast about the wide coverage that they have.

I suppose having one frequency in parts of The Ottawa Valley is how they cover that part. There is one in Pembroke as well. And other places too, although the only one I'd be able to hear if there is activity is the one I was talking about because of the range that it would have.

Antenna locations and Coverage area can be seen here. http://www.cwcom.com/cwcom/antenna.htm

 

[DaveH]

I believe the Renfrew site IM is referring to is LTR-Net,
(or ESAS) not Passport, as the interval of the carrier burst
is 1-1/4 seconds. I think it is networked but have not heard
anything on it myself...but it is still operating.

There is no category in the TRS DB for LTR-Net. To avoid
confusion with LTR Multi-Net, it ended up as LTR Regular.

One needs to be careful with some of these TAFL listings...
they can be out of date and somewhat (inadvertantly) misleading.
It's taken considerable time to weed through this.

Ottawa 1000 Castlehill
858.087500 858.337500 858.587500 858.837500 859.087500

This was the last of two Midland CMS systems in Ottawa that
finally went off the air a couple of years back. I saw pieces
of it for sale at an ham fleamarket (or that could have been the
second-last system...). One of the systems used CTCSS (same on
all channels), and the other did not use CTCSS. It was the same
tone for all users (162.2).

Ottawa Place De Ville Twr C site are
853.387500 853.637500 853.887500 854.137500 854.387500
860.112500 860.612500 860.737500 861.112500 861.362500 861.612500

This site listing is a mix of LTR-Net, regular LTR, and EDACS.
VAV700 {853.387500 853.637500 853.887500 854.137500 854.387500}
was LTR-Net and is no longer operating; that's why it never made
it to the TRS DB. I suspect the licensee is sitting on these channels
until figuring out what to do with them.

{860.112500 860.612500 860.737500 861.112500 861.362500 861.612500}
contains the Message Centre EDACS system and some old LTR channels
that are no longer active or were never active. There is no indication
of Passport being used in Ottawa.

http://www.radioreference.com/modules.php?name=TRSDB&sid=1790


I'm not sure about the others; will check my back in my files.

Dave

 

[EricCottrell]

Hello,

Thanks for the information.

The LTR-Net down in RI and in NY state I monitored had a status channel and a normal time between idle bursts. LTR systems are flexible so it could be LTR-Net.

I will put these systems on my list of targets for the next visit to Carp. If it is LTR-Net I can tell from the frames. I have not received a known ESAS system yet, so it will be interesting if it is ESAS.

Recently I was able to figure out some of the LTR-Net protocol so it will eventually work it's way into LTRDump/LTRTrunk.

73 Eric

 

[DaveH]

Eric,

I believe it to be LTR-Net or ESAS. One of the systems (VAV700, off the air) had users with interconnect capability (full duplex). They made mention of Viking (Johnson) equipment. The user ID's were LTR-compatible, which would be the back-compatibilty of LTR-Net with LTR (had read patents for both types of systems).

The idle pattern is eight fast bursts (which are not decoded by LTRDump as LTR) with one LTR burst i.e. every 10 seconds (which can be decoded). Another system east of Ottawa (Rockland) is similar, and I decoded a user using an LTR receiver:

http://www.radioreference.com/modules.php?name=TRSDB&sid=2999

Dave

 

[IdleMonitor]

Dave. Is it possible to put the only frequency known on this local system into all my LTR slots and hope atleast a CW ID shows up on one of them and then I would have atleast the correct LCN.

Otherwise, I doubt I'll hear very much if anything on this system.

 

[EricCottrell]

Eric,

I believe it to be LTR-Net or ESAS. One of the systems (VAV700, off the air) had users with interconnect capability (full duplex). They made mention of Viking (Johnson) equipment. The user ID's were LTR-compatible, which would be the back-compatibilty of LTR-Net with LTR (had read patents for both types of systems).

The idle pattern is eight fast bursts (which are not decoded by LTRDump as LTR) with one LTR burst i.e. every 10 seconds (which can be decoded). Another system east of Ottawa (Rockland) is similar, and I decoded a user using an LTR receiver:

http://www.radioreference.com/modules.php?name=TRSDB&sid=2999

Dave

Hello,

Then I would say it is ESAS. LTR-Net uses the area bit and illegal combinations for the extended features so on a area 0 system the extended frames are area 1 using repeater numbers like 24 or 26. ESAS uses an inverted sync for extended frames.

I would be interested if you tune into this system and flip the invert setting in LTRDump. I want to see if they use the same check system and if LTRDump just has to recognize inverted frames for ESAS. I want to add ESAS decoding but I do not have any known systems around me.

73 Eric

 

[DaveH]

I would be interested if you tune into this system and flip the invert setting in LTRDump. I want to see if they use the same check system and if LTRDump just has to recognize inverted frames for ESAS. I want to add ESAS decoding but I do not have any known systems around me.

73 Eric

Eric,

I could try LTrunk but not on the Rockland system...it is just out of range. LTRTrunk/
LTRDump don't run on my old (new) laptop; maybe Ltrunk will, need to try it.

At any rate there is at least one other system I can hear, so will try that one. There
is no way to tell from the database which of these is plain old LTR and which are
(we think) ESAS or LTR-Net. Best that can be done is adding a note to the record.

Something else I've noticed is occasionally a funny "talkgroup" sometimes wanders
up through the channels, sending out two audio "beeps" and then goes away. Any
idea what that would be?

Dave

 

[DaveH]

Is it possible to put the only frequency known on this local system into all my LTR slots and hope atleast a CW ID shows up on one of them and then I would have atleast the correct LCN.

You could try that for the cost of tying up 20 channel slots. Not every system
seems to ID (at least with the x-xx-253 Group ID). I've never heard activity on
this one, but it's still there, and may have occasional low-level usage. The only
way to find out is to monitor for awhile.

If it doesn't ID and there are no users, the repeater number may be
interesting, but not very useful. There was another frequency in use, 852.9375.
I'm pretty sure it's gone but you might want to check for it.

Dave