Not sure where/how to post this. I us my SDR dongle and SDR# like a poor man spectrum analyzer and digital decoder.

[merlin]

I have 2 signals that are just vague where ID is concerned. one I believe is a P25 control channel and one I would like to decode.
Reminds me most of NXDN but very odd. First image is waterfall, second is IF, 3rd is audio bandpass.
Anybody certain what this signal is?
Lastly, the control channel (?) it is too weak to see on my real analyzer, well above the noise on the SDR. Just barely breaks squelch on my UV5-r.
Anyone certain what flavor this channel is, Been looking for state police, but believe they are up on 700 Mhz.

 

[mmckenna]

What's the center frequency?

In the FCC database, there are several casinos and other users on 462.025 running DMR repeaters.

 

[merlin]

The control channel is 457.055, the NXDN (?) is 462.03
Both in Pocatello Idaho (region 5) I find nothing for these on the FCC database. I thought one/other/both would auto identify but so far, no.
What I am wanting is specifics for these so I can decode them with such as DSD+ and unitrunker. There are plenty of BDAs in town but they are on 700-800 Mhz with WiMax repeaters.

 

[merlin]

The images show frequency,BW, and audio BP.

 

[N6ML]

I don't think you said what your "real analyzer" is, or what your "SDR dongle" is, but if you're not seeing these signals on a "real analyzer", I'd suspect that they are some sort of byproducts (from strong signals elsewhere) being generated in the front-end of your SDR.

 

[mmckenna]

Ah, OK. Your location shows as "lasvegas,nv." which lead me to believe that's where you were located.

Might be these guys: ULS License - Industrial/Business Pool, Trunked License - WPPV355 - TETON COMMUNICATIONS INC
They have mobile stations as part of a trunked network on 457.050 with emission designators for DMR and Very Narrow NXDN.
467.055 is not a legitimate frequency in the Business/Industrial frequency pool. 457.050 or 457.05625.

White Cloud Communications has 462.025MHz repeater running NXDN out of Burley ID: ULS License - Industrial/Business Pool, Trunked License - WRCC373 - WHITE CLOUD COMMUNICATIONS

 

[merlin]

I don't think you said what your "real analyzer" is, or what your "SDR dongle" is, but if you're not seeing these signals on a "real analyzer", I'd suspect that they are some sort of byproducts (from strong signals elsewhere) being generated in the front-end of your SDR.

No, I didn't because it is pointless. My bench spectrum analyzer is HP 8590A in excellent working condition.
The SDR is Noo NESDR smarT with Scientific Atlanta MMdrop amp front end and folded dipole antenna indoors.
Running SDR# with DSD+ and Unitrunker as I have been a few years
Using a 1 foot alligator test jumper as the antenna on the HP which explains the lack of weak signals.
The signal is there, weak reception with my UV-5R. The deal with this is sigidwiki doesn't have a close match for ID, the closest, perhaps NXDN.
Sadly, I went dicking with the mic input and disabled it, now can't enable it, that in turn fails DSD+ from working so have to fix that anyway.
Nonetheless thanks for your input, covering what can go wrong is wise.
73s

 

[merlin]

Ah, OK. Your location shows as "lasvegas,nv." which lead me to believe that's where you were located.

Might be these guys: ULS License - Industrial/Business Pool, Trunked License - WPPV355 - TETON COMMUNICATIONS INC
They have mobile stations as part of a trunked network on 457.050 with emission designators for DMR and Very Narrow NXDN.
467.055 is not a legitimate frequency in the Business/Industrial frequency pool. 457.050 or 457.05625.

White Cloud Communications has 462.025MHz repeater running NXDN out of Burley ID: ULS License - Industrial/Business Pool, Trunked License - WRCC373 - WHITE CLOUD COMMUNICATIONS

Old addy by 6 years, never bothered to update. Burly is 80 miles and the site a tad west of that on a bit of hilltop. I won't be getting UHF from there without a hell of a Yagi well above the roof. This signal is close, -96Db on a small indoor folded dipole.
This signal in question is at 462.025 and what I suspect is a control channel is at 457.05. FCC comes up with nothing in my region for these frequencies but they have to be close, Pocatello/Chubbuck is surrounded by mountains. All of our first responders have dropped VHF and county maintenance soon to leave that only gives me a few private business to listen to. Scanner forums say the state and county has gone 700 Mhz but nothing there but cell phone. Another note is neither of these signals auto identify making it that much harder.

 

[Ubbe]

If that UV-5R are the only portable you have, then go to different high points in your area and try to listen with the squelch open. If you get a more cleaner signal then compare when listening to known frequencies of different system types and try to match the sound. If you do not manage to get any signal then it has to be the SDR dongle that have mixing products that are easy to get when using amplifers. SDR dongles are terrible receivers when it comes to ghost frequencies and band scanning for new frequencies.

/Ubbe

 

[mmckenna]

Another note is neither of these signals auto identify making it that much harder.

There doesn't appear to be any licenses showing on the FCC database that would explain that.

Which would suggest one of the following:
Demonstration system operating under some shops license. I'd expect that to be short term trial use.
Someone operating without a license.

That's where footwork and a directional antenna comes into play.

 

[merlin]

If that UV-5R are the only portable you have, then go to different high points in your area and try to listen with the squelch open. If you get a more cleaner signal then compare when listening to known frequencies of different system types and try to match the sound. If you do not manage to get any signal then it has to be the SDR dongle that have mixing products that are easy to get when using amplifers. SDR dongles are terrible receivers when it comes to ghost frequencies and band scanning for new frequencies.

/Ubbe

The UV-5R is just a radio I keep around, it serves most getting frequencies narrowed although my SDR is quite accurate. I would us it more if only I could tap the discriminator output before de-emphasis and filtering to pipe for DMR decoding. Looking to a new scanner for that.
The spectrum analyzer meets FCC tolerances once I get past the self calibration.

 

[merlin]

There doesn't appear to be any licenses showing on the FCC database that would explain that.

Which would suggest one of the following:
Demonstration system operating under some shops license. I'd expect that to be short term trial use.
Someone operating without a license.

That's where footwork and a directional antenna comes into play.

Seems FCC regs are playable where state and county are concerned. Left up to state and county group (one of those 3 letter things) to decide frequencies for first responders outside of firstnet. These odd signals just may be them but won't know until I can decode them.
Broke the sound in on my PC, spent 12 hours fixing that. Now if DSD+ will decode anything it will be progress.