Can you Identify this control channel sound ?

[FLANO]

Hello,

We've been getting reports from Phoenix area of a new machine gun sounding control channel active in the 160-170mhz range. I took a quick spin in my neck of the woods, Tucson, and came up with one fairly strong signal (172.2375mhz) and a weak one (163.8375mhz).

I am attaching a 10 second clip. It is not decoding with Unitrunker, and I don't recognize this signal. I am very familiary with the sound of Motorola's systems.

Anybody?

Thanks in advance

[shaft]

Can you re-zip it and attach it again, Im getting file corruption errors in WinZip and Winrar.

[FLANO]

Ok, here's a new one that popped up loud and clear on 173.05mhz.

Thanks in Advance,

[shaft]

Im still getting a bad offset error when trying to open it up. Im wondering if the file is getting a lil corrupted when uploaded.

[rescue161]

What kind of scanner are you using to decode it with UniTracker? We have a UHF system here that sometimes cannot be tracked with my Uniden scanners. There is a slight high-pitched sound over the CC that keeps the scanners from decoding the CC data. Could that be the case here? Have you tried to invert the signal? It sounds like a Motorola CC to me.

[Josh]

sounds like a standard Motorola smartzone controller to me.

-Josh

[slicerwizard]

Originally Posted by Josh

sounds like a standard Motorola smartzone controller to me.

Ditto. Would be nice if it was discriminator audio and a bit longer.

[FLANO]

That audio is coming off the discriminator tap of a PRO-2006, PCM, 22khz, Mono. I kept it to 10 seconds due to the size constraint allowed for zipped files.

I use Unitrunker everyday with this radio, so I know it is working. The sound is a bit off from the other Motorola control channels that we have down here. I will try inverting it to see what happens.

The DOJ TRS is suppose to happen for us down here in AZ. The frequency range is right, but having a heckuva time with this.

Thanks for the feedback. I'll let you know.

[FLANO]

This has literally been on the air only days, so perhaps a test mode? This could explain why no signal recognition by Unitrunker as a valid Motorola signal. If anyone would like a longer clip, let me know. I'll have to e-mail it to you.

[rescue161]

Did you try inverting the signal in UniTrunker yet?

[ChrisP]

Originally Posted by FLANO

This has literally been on the air only days, so perhaps a test mode? This could explain why no signal recognition by Unitrunker as a valid Motorola signal. If anyone would like a longer clip, let me know. I'll have to e-mail it to you.

John, for what it's worth - When the Justice IWN trunked sites were coming on the air up in the Pacific Northwest, we did hear a signal similar to the clips you posted. There were all sorts of assumptions that this was Open Sky, Pro Voice or some new form of encryption.

We didn't know exactly we were listening to, but I heard that this was some sort of test signal that was used for P-25 coverage, signal strength and multipath testing. I can't recall how long they kept these signals on the air, but eventually they turned in to P25 voice and trunked control channels.

Keep us posted and see what else pops up down there...

- Chris

[dmills1]

It sounds to me like a V.52 data test pattern. The pattern is used for testing BER and also used by Motorola as the data pattern sent over the air for coverage testing a system.

Dennis

[FLANO]

Thanks to everyone for your help.

I'm sitting on one of the frequencies, exclusive to anything else. Unitrunker is running, so hopefully we'll get a Project-25 control channel over the frequency. I will try to make a new longer copy of the signal for future ID of this test pattern.

This is a good topic on the ArizonaScanner Yahoo group, and we have a number of ears listening for this event.

Thanks again,

[wayne_h]

Originally Posted by dmills1

It sounds to me like a V.52 data test pattern. The pattern is used for testing BER and also used by Motorola as the data pattern sent over the air for coverage testing a system.

I concur with Dennis. A lot of the time when new sites come up on the air Motorola enables what Dennis describes and it's commonly mistaken for a CC.

[FLANO]

Hey Wayne,

That's ok too. Based on the previous posting to that one by Chris P, this may very well be the prelude or the warning for us in Arizona to start paying attention for the real thing - the activation finally of DOJ TRS in Arizona

I went back and compared the audio of this signal to the other Motorola control channels in our area, running them side by side. I've been fortunate to catch the prepping for weeks ahead, and actual switch over of our Electric Company from a Type II to a Project-25 system. They did not run these test patterns prior to switching. So, another new thing to add, when looking at new Motorola TRS installations in our area.

Collectively, we in Arizona have identified seven or eight potential frequencies for the TRS when it goes active.

[ChrisP]

One other thing we noticed when the IWN sites around Portland, OR were being set up. Searching through the VHF federal band, in addition to the test pattern transmissions, we found many of the future voice channels from the trunked sites transmitting with no modulation. They would sometimes be transmitting for hours at a time over a period of several days. We made note of what frequencies these dead carriers were heard, and sure enough, once the system was up and running, many of them turned out to be voice channels.

Once the system is up, you might begin to hear some clear voice tests of a recording that seems to test the digital vocoders. It's a nonsensical sentence that keep repeating over and over. I think I caught an MP3 of the one we heard in Portland. The chatter from the radio techs when they get these sites up is also fun to listen to, up until they enable the encryption...

- Chris

[roadranger]

I did the math, so it isn't an image frequency, but without looking at my paper logs, 172 mhz falls on wireless microphones, and maybe even baby monitors. Is it possible that another listner near by hasn't quite figured out his/her trunktracker and is trying to listen to it through another wireless device? I mean why listen to one scanner with another, that way? It could explain the odd frequency.

[roadranger]

172.2375 falls under federeal/dispatch on an archives list from MT magazine. (162.01250-173.2 MHZ)
Also, under Public Safety, Mobile low power wireless mikes, MT magazine. (169-172 MHZ)
Thanks to Monitoring Times, and Mr. Larry Van Horn Asst. Editor.

[roadranger]

Originally Posted by FLANO

Ok, here's a new one that popped up loud and clear on 173.05mhz.

Thanks in Advance,

Genreal Scanning Forum; I beleive this is under Lo Jack; ScannerQSL? Anyway what you may have found is LOJACK in your area! I stumbled across this moments ago! This sould appear under 173.05 / .075

[FLANO]

Originally Posted by roadranger

Genreal Scanning Forum; I beleive this is under Lo Jack; ScannerQSL? Anyway what you may have found is LOJACK in your area! I stumbled across this moments ago! This sould appear under 173.05 / .075

Short answer, no.

I am very familiar with the audio sound for Lojack. I am also very familiar with trunking channel sounds. I was questioning this one, as it did not fit the audio of the systems in our area. It seems to have turned out to be a test pattern for the hopefully soon to be trunked system for DOJ in our area.

All of the signals have since gone quiet....

Tweaking the system I hope