Unknown P25 System

[mciupa]

An American hobbyist in Rochester is picking up some P25 VHF signals which he is presuming originate in Ontario, possibly between Oshawa and Kingston.

I'll put up the data here. It may have to be tweaked to the Canadian band plan, however.

Data as follows:

SysID 002
WACN 00001


Site 1, RFSS 1
150.2375d

Site 2, RFSS 2
150.2475d

Site 3, RFSS 3
152.0600d
152.2700a
152.4600a
154.5150a
Site Neighbors 1, 2


It may very well be an American system but if it isn't, I'd appreciate if you can help with identification or throw some ideas out there.

Thanks!

 

[VA3DBJ]

I have them plugged in here in Bowmanville. Nothing coming up so far. Depending on power, the 150's I usually get as far as Brighton-Trenton.


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[k2hz]

I am the one hearing this in Rochester NY.

I am only receiving the 152.060 Control Channel. All other frequencies are as being indicated by the CC data. Reception varies from moderately strong to almost unreadable in the noise and the variations since I heard it strong on Saturday have been consistent with variations in known signals from the Lake Ontario N shore area such as 156.55 Seaway Newcastle and 161.65 Cobourg weather.

During the period when reception was particularly good I was also getting a good signal from the Belleville FD on 153.830 so reception appeared to be enhanced by ducting over the lake.

I can not hear the reported 150.2375 and 150.2475 CCs from the other sites. These are Military frequencies in the US which is another reason I suspect Canadian origin.

The CC data has not shown any active TGs on the system during times of good reception here so activity other than the CC frequencies is unlikely.

I have not ruled out a US source but was looking for any known systems before I go out hunting for it.

I hoped that someone would recognize the system or be able to receive the other 2 reported sites that I can not hear and are on odd frequencies.

Thanks for any comments.

 

[k2hz]

Update-

When I hear odd signals I always suspect it is testing from the local Harris RF facilities. It did not seem likely in this case due to strength and fading characteristics of the signal.

I went out today to eliminate Harris as a possibility. I checked with a handheld outside the 4 Harris facilities I am aware of and heard nothing on 152.060. I also heard nothing at other locations around the area so the signal does not seem to be local to Rochester.

The mystery continues.

 

[VA3DBJ]

I have checked the IC's database for 152.060 and nothing is showing up for southern Ontario region. All licences coming up are for Algonquin region and north. If it is here, it is either a very new licence or it is being protected.


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[k2hz]

I have checked the IC's database for 152.060 and nothing is showing up for southern Ontario region. All licences coming up are for Algonquin region and north. If it is here, it is either a very new licence or it is being protected.

I has also checked Canadian licenses and found no match when I first heard the signal. There are several licensed systems here in NY on 152.060 that are a possibility but the 150.2xxx frequencies the system is reporting for the other 2 sites are not legitimate for any civilian use in the US. Also some of the reported associated mobile frequencies for the site did not appear legitimate for a US user.

The lack of any apparent users on the system and the odd mix of frequencies would tend to indicate an experimental operation of some kind but I can't blame it on the local Harris people.

If nothing is being heard in Canada on 152.060, 150.2375 or 150.2475 and the WACN and SysID do not seem to relate to any known system in your area it is probably fair to assume it is not in Canada.

Thank you and Mike for checking! If I find any new information I will let you know.

 

[k2hz]

This gets stranger but it apparently is some type of experimental system.

The P25 control signal disappeared sometime yesterday afternoon and has been replaced by 3 seconds of unmodulated carrier at intervals of about 5 minutes. I am seeing the same long term variations in signal strength apparently from propagation conditions for a distant signal.

As I write this, it has keyed up several times with a few seconds of a digital signal that DSD+ does not recognize.

I don't see much hope of identifying it and, since it is not a new trunked system, there is little value in any more observations.

Thanks again for your assistance.

 

[Jay911]

I has also checked Canadian licenses and found no match when I first heard the signal

One thing you need to be aware of with regards to Canadian licensing records if you don't already know: it is possible to have your records hidden from public view, aka "protected". In such a situation, even a direct search on a single frequency or a known callsign, etc., will result in "no records found". The only people who can see the records for protected licenses are the licensee and the Spectrum Management (government) folks.

It's not uncommon to have law enforcement and some government entities protected by default. Almost all federal and all military are absolutely protected. (Canadian licenses are not managed by two agencies like FCC and NTIA; all licenses, including the ones for governmental agencies and military, are in the one records system, as far as I know.)

So it's entirely possible that the system is Canadian, but not visible on licenses to the public.

Regarding the testing you witnessed - when the new P25 system in my area was being built out, it was not unusual to have 1050 Hz tone on frequencies for days at a time while they configured and optimized transmitter power, antenna placement, etc. Sometimes it was analog, sometimes it was in P25 CAI. Could that be the signal that you heard but DSD+ wouldn't translate? A steady tone played in P25 CAI has a distinct sound to it when listened to in analog mode - if a control channel sounds like a diesel engine at idle, 1050 Hz on P25 CAI sounds like a diesel engine at about 4 grand RPM.

 

[k2hz]

Thanks for the info.

I knew about IC omitting "protected" systems which I assumed were only extremely sensitive government operations but apparently it is more extensive that that.

I have also observed simulcast systems under construction transmitting not only a tone but also a non-P25, unrecognizable, continuous digital signal that I believe is a BER test pattern. The digital bursts I am hearing at times today sound like what is typically a SCADA or telemetry system that uses a proprietary protocol. This activity has been infrequent so far.

All things considered, I think this P25 was an experimental signal. The frequency data that was being transmitted for some receive frequencies for this site and the other site Control Channels appear to be bogus, just arbitrary numbers to fill those fields in data stream. The lack of any apparent Trunk Group activity and the fact the the other sites may not even exist also makes it doubtful this was a legitimate system.

 

[DaveH]

Interesting, though I'm a bit far north/east of this system to comment directly, I'm keeping an ear
on that part of the band (150~154) for new systems.

Most of what I hear up here are in Quebec (RENIR, P25), a bit of DMR, and a mix of NXDN 4.8k and 9.6k systems.
In enhanced conditions, some P25 CCs for NYSEG system come through.

Military in Canada seem to span the 138-174 band, some frequencies exclusive but others shared with other services
although not in the same area. DND has a VHF P25 system (5DE) but this new one doesn't seem to fit its MO closely.

150.2375 could be Canadian (on 15/7.5kHz grid) or American (on 25/12.5kHz grid). Not sure about 150.2475,
can that be confirmed, does not seem to fit either, even using 6.25kHz. Also, 152.460 looks rounded off, probably
152.4575 (7.5kHz step).

I suspect as soon as somebody DFs one or more sites, part of the question will be answered.

Dave

 

[mikewazowski]

150.2450Mhz is a frequency in use at CFB Borden.