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NXDN and DMR on lots of frequencies

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Ghstwolf62

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Not sure if you are aware of this, but there is a file in your DSDPlus folder that is called "aliases". It contains all of the RID's (including names of users) and TG's. Just make sure you hit escape when you exit DSDPlus so that newly captured ones are saved to the file.
Here's mine so far:

https://www.dropbox.com/s/40x4x81849f45pd/DSDPlus.aliases?dl=0
Question for you, I've never had such a file and there is not one in there now. Is there some special way of initiating it to be created?

I have used the "Esc" button as you said since I read this but no file still and I ran it for hours last night after seeing this.

Thanks
 

bcorbin

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Bonus - the 450.150 system is busy in a big way at the moment, and it looks like:

; NID 105 Site 5 Ran 5 NL 1 2 3 4
NEXEDGE48, 105, 5, 22, 450.13125, 0.0, 0
NEXEDGE48, 105, 5, 25, 450.150, 0.0, 0
NEXEDGE48, 105, 5, 28, 450.16875, 0.0, 0
 

bcorbin

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After staring at 105/5 for a minute or two, I realized that the folks who run that system had more than likely mapped the 450-451 band directly onto their channel line-up. Sure enough, it looks like the following works:

freq = 450.0000 + (Ch - 1)*0.00625

I think that means Nick's Ch 51 logging is actually on 450.3125.

I think these Nexedge signals are a little wide for 0.00625 KHz resolution - I'm still not entirely sure whether the control channel I think I'm hearing at 454.400 is actually on 454.400 or 454.40625 - I can set up on either and decode just fine...
 

jazzbassNick

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Hmmm....entirely possible. I thought what I had in my notes looked a little funny.
Since you found a formula that works for SID 105, maybe I'll try to hit that first when I get back at it.
 

bcorbin

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I had a little time to put together some notes on how to figure out whether or not the frequency table is being generated by a linear formula...

The 'right' way to do this is to plot frequency (f) vs channel number (N) and try linear regression on the straight segments.

...but in a pinch, the following will do:

Take two channel/frequency pairs: N1/f1 and N2/f2

... the trial equation will look like:

f = (f2 - f1)/(N2-N1) * (N-1) + [ f1*(N2-1) - f2*(N1-1) ]/(N2-N1)

(the first term will give you the trial step size, the second term the trial base frequency)

Once you've got the form, try some N3 and see if it gives you the correct value for f3 - if so, chances are pretty good that they've used a linear map (try several values of N to gain more confidence).

It is possible that several lists/functions have been appended to one another - so the pairs you use should be in the same band to begin with.
 

jazzbassNick

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@bcorbin

You nailed it. Was just checking out a troublesome rtl stick I had and 450.3125 is indeed the correct freq. Judging by the TG names of "AIR 7 Radio 1" and "Desk A", it totally jives with the ULS search.

Great call!
 

AA6IO

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Listening to DMR on 453.000 via DSD+ at 2 AM New Years Morning. Constant traffic on both slots 1/2. TGs = 3, 73, 82 among others. RIDs are multiple ranging in 3000-5000. Sounds like parade officials setting up everything for the parade later this morning. Lot of references getting horses ready, grandstand preparation, parade rehearsal, crowd control, interactions with safety officers. This seems to be part of a trunk system (CC=1), and the traffic on 453.000 is constant. Excellent decode.

Can find no information about any licenses for DMR at this frequency. Frustrating not being able to identify, but very interesting. Perhaps I am just not aware how to search the FCC database specifically for DMR, or even if channels listed in this manner.
Provides an incentive for me to learn more about DMR. and how to ID systems.
Steve AA6IO

Steve AA6IO
 

bcorbin

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Very cool!

I stumbled on a couple more this morning - I suspect they're both up in the AV -

461.5375 - NXDN 48, RAN 18. (I've logged four different TG's on this so far)

461.800 - DMR, DCC 6, Ch 1

I have not found any CC's or alternate voice channels associated with either system - so they *might* be stand-alone...

Happy New Year, all...
 

jazzbassNick

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Gents,

Ran across a Con+ control channel that I can't seem to properly flesh out.
Freq is 454.51875 (using FMP & DSDPlus 1.074)
ID'd 433-2, with NLs of 1 and 3 but DSDPlus activity also shows an entry of 433-128 and 433-32.
FCC ULS entry shows "Part 22 VHF/UHF Paging (excluding 931MHz) License - WPVF230 - Metropolitan Water District of Southern Calufornia" (their typo not mine hee hee).

The only radio activity I've found in the log was this:
Code:
2015/05/29  09:48:48  Group call; TG=107  RID=1404 [Unit 30]    2s
2015/05/29  09:49:28  Group call; TG=76  RID=991 [Unit A-4...]    1s
I had the thought that it might be some automated monitoring/reporting of equipment, but I dunno.

Thoughts or any additional data you might've found?
Thanks,
N
 
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jazzbassNick

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This happened last night:
Code:
2015/06/01  23:31:25  Group call; RID=4260608  Ch=65535  AlgID=00  
2015/06/01  23:42:47  Emerg Enc Bcast OVCM Private call; Tgt=12809  Src=53735   Slot=1s Pri3    Alg=BP
 

bcorbin

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Funny - one thing led to another, and I've been off doing HF digital for the last six months 8*)

Anyway, thought I'd turn on the V/UHF gear for a bit, and low-and-behold a new system has popped up near Santa Clarita:

;NID: 433 Site 6 DCC 1 NL 3 4 5 7 8
Con+, 433, 6, 1, 453.5125, 0.0, 0
 

bcorbin

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Add 453.2375 to 433/6

Funny - one thing led to another, and I've been off doing HF digital for the last six months 8*)

Anyway, thought I'd turn on the V/UHF gear for a bit, and low-and-behold a new system has popped up near Santa Clarita:

;NID: 433 Site 6 DCC 1 NL 3 4 5 7 8
Con+, 433, 6, 1, 453.5125, 0.0, 0
 

bcorbin

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...and we have a winner....

;NID: 433 Site 6 DCC 1 NL 3 4 5 7 8
Con+, 433, 6, 1, 453.2375, 0.0, 0
Con+, 433, 6, 1, 453.4125, 0.0, 0
Con+, 433, 6, 1, 453.5125, 0.0, 0

...and it looks to be a perfect match for the Metropolitan Water District's site on Oat Mtn...
 

bcorbin

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...and it would appear that we can add

Con+, 433, 6, 1, 451.1125, 0.0, 0

to the list. The interesting thing is, IIRC and my old notes are worth anything, these frequencies used to be reserved for low-power use....


...and we have a winner....

;NID: 433 Site 6 DCC 1 NL 3 4 5 7 8
Con+, 433, 6, 1, 453.2375, 0.0, 0
Con+, 433, 6, 1, 453.4125, 0.0, 0
Con+, 433, 6, 1, 453.5125, 0.0, 0

...and it looks to be a perfect match for the Metropolitan Water District's site on Oat Mtn...
 
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