trunk recorder center?

[da2ricky]

Hi,

I'm trying to get trunk recorder working with 1 RTL dongle on ubuntu. I have/had op25 working without issue but I really want to use trunk recorder/player.

I'm not getting any recording but I can see TGID's being monitored. I've fiddled around with the center number and it SOMETIMES records but often just gives the error "no source covering freq". I have no idea how to find the center freq...

I'm trying to monitor a P25 Phase II system with a control channel of 853.7875

Here's the output from trunk recorder:

linux; GNU C++ version 7.3.0; Boost_106501; UHD_003.010.003.000-0-unknown

[2019-10-13 20:24:22.656572] (info) Using Config file: ./config.json

[2019-10-13 20:24:22.657178] (info)
-------------------------------------
SYSTEMS
-------------------------------------
0
[2019-10-13 20:24:22.657293] (info)

System Number: 1
-------------------------------------
1
[2019-10-13 20:24:22.657376] (info) Short Name: Onslow P25
[2019-10-13 20:24:22.657407] (info) System Type: p25
[2019-10-13 20:24:22.657437] (info) Control Channels:
[2019-10-13 20:24:22.657509] (info) 8.53788e+08
[2019-10-13 20:24:22.657574] (info) API Key:
[2019-10-13 20:24:22.657610] (info) Upload Script:
[2019-10-13 20:24:22.657641] (info) Call Log: true
[2019-10-13 20:24:22.657676] (info) Audio Archive: true
[2019-10-13 20:24:22.657705] (info) Loading Talkgroups...
[2019-10-13 20:24:22.657746] (error) Error Opening TG File: talkgroups.csv

[2019-10-13 20:24:22.657786] (info) Talkgroups File: talkgroups.csv
[2019-10-13 20:24:22.657826] (info) Record Unknown Talkgroups: true
[2019-10-13 20:24:22.657859] (info) Talkgroup Display Format: Id
[2019-10-13 20:24:22.657891] (info) Hide Encrypted Talkgroups: false
[2019-10-13 20:24:22.657922] (info) Hide Unknown Talkgroups: false
[2019-10-13 20:24:22.657952] (info) Minimum Call Duration (in seconds): 0
[2019-10-13 20:24:22.657985] (info)
[2019-10-13 20:24:22.658013] (info)

-------------------------------------
SOURCES
-------------------------------------

[2019-10-13 20:24:22.658108] (info) Driver: osmosdr
[2019-10-13 20:24:22.658156] (info) Center: 8.535000e+08
[2019-10-13 20:24:22.658207] (info) Rate: 2048000
[2019-10-13 20:24:22.658250] (info) Error: 1000
[2019-10-13 20:24:22.658287] (info) PPM Error: -2
[2019-10-13 20:24:22.658323] (info) Gain: 37
[2019-10-13 20:24:22.658360] (info) IF Gain: 0
[2019-10-13 20:24:22.658391] (info) BB Gain: 0
[2019-10-13 20:24:22.658423] (info) LNA Gain: 0
[2019-10-13 20:24:22.658454] (info) PGA Gain: 0
[2019-10-13 20:24:22.658485] (info) TIA Gain: 0
[2019-10-13 20:24:22.658517] (info) MIX Gain: 0
[2019-10-13 20:24:22.658548] (info) VGA1 Gain: 0
[2019-10-13 20:24:22.658579] (info) VGA2 Gain: 0
[2019-10-13 20:24:22.658611] (info) Squelch: 0
[2019-10-13 20:24:22.658642] (info) Idle Silence: false
[2019-10-13 20:24:22.658673] (info) Digital Recorders: 4
[2019-10-13 20:24:22.658707] (info) Debug Recorders: 0
[2019-10-13 20:24:22.658737] (info) SigMF Recorders: 0
[2019-10-13 20:24:22.658766] (info) Analog Recorders: 0
[2019-10-13 20:24:22.658798] (info) Modulation: qpsk
[2019-10-13 20:24:22.658826] (info) Both PPM and Error should not be set at the same time. Setting Error to 0.
[2019-10-13 20:24:22.658859] (info) Source Device: rtl=0
gr-osmosdr 0.1.4 (0.1.4) gnuradio 3.7.11
built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy airspyhf soapy redpitaya freesrp
Using device #0 Realtek RTL2838UHIDIR SN: 00000001
Found Rafael Micro R820T tuner
[R82XX] PLL not locked!
[2019-10-13 20:24:23.255545] (info) SOURCE TYPE OSMOSDR (osmosdr)
[2019-10-13 20:24:23.255711] (info) Setting sample rate to: 2048000
[R82XX] PLL not locked!
[2019-10-13 20:24:23.372091] (info) Actual sample rate: 2048000
[2019-10-13 20:24:23.372190] (info) Tunning to 8.535000e+08
[2019-10-13 20:24:23.423735] (info) Gain Stage: LNA supported values: 0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48 49.6
[2019-10-13 20:24:23.423803] (info) Max Freqency: 8.545240e+08
[2019-10-13 20:24:23.423847] (info) Min Freqency: 8.524760e+08
[2019-10-13 20:24:23.449220] (info) LNA Gain set to: 0
[2019-10-13 20:24:23.474583] (info) TIA Gain set to: 0
[2019-10-13 20:24:23.499956] (info) PGA Gain set to: 0
[2019-10-13 20:24:23.525490] (info) Gain set to: 37.2
[2019-10-13 20:24:23.525594] (info) Setting antenna to [RX]
[2019-10-13 20:24:23.599776] (info) P25 Recorder Initial Rate: 512000 Resampled Rate: 30117.6 Initial Decimation: 4 Decimation: 17 System Rate: 30000 ARB Rate: 0.996094
[2019-10-13 20:24:23.599864] (info) P25 Recorder Taps - initial: 311 channel: 1551 ARB: 731 Total: 2593
Project 25 IMBE Encoder/Decoder Fixed-Point implementation
Developed by Pavel Yazev E-mail: pyazev@gmail.com
Version 1.0 (c) Copyright 2009
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions; see the file ``LICENSE'' for details.
[2019-10-13 20:24:23.615040] (info) P25 Recorder Initial Rate: 512000 Resampled Rate: 30117.6 Initial Decimation: 4 Decimation: 17 System Rate: 30000 ARB Rate: 0.996094
[2019-10-13 20:24:23.615118] (info) P25 Recorder Taps - initial: 311 channel: 1551 ARB: 731 Total: 2593
[2019-10-13 20:24:23.638893] (info) P25 Recorder Initial Rate: 512000 Resampled Rate: 30117.6 Initial Decimation: 4 Decimation: 17 System Rate: 30000 ARB Rate: 0.996094
[2019-10-13 20:24:23.638983] (info) P25 Recorder Taps - initial: 311 channel: 1551 ARB: 731 Total: 2593
[2019-10-13 20:24:23.654187] (info) P25 Recorder Initial Rate: 512000 Resampled Rate: 30117.6 Initial Decimation: 4 Decimation: 17 System Rate: 30000 ARB Rate: 0.996094
[2019-10-13 20:24:23.654265] (info) P25 Recorder Taps - initial: 311 channel: 1551 ARB: 731 Total: 2593
[2019-10-13 20:24:23.659906] (info)
-------------------------------------


[2019-10-13 20:24:23.659962] (info)

-------------------------------------
INSTANCE
-------------------------------------

[2019-10-13 20:24:23.660022] (info) Capture Directory: /home/op25/trunk-build
[2019-10-13 20:24:23.660044] (info) Upload Server:
[2019-10-13 20:24:23.660236] (info) Status Server:
[2019-10-13 20:24:23.660260] (info) Instance Key:
[2019-10-13 20:24:23.660280] (info) Instance Id:
[2019-10-13 20:24:23.660300] (info) Default Mode: digital
[2019-10-13 20:24:23.660321] (info) Call Timeout (seconds): 3
[2019-10-13 20:24:23.660343] (info) Log to File: false
[2019-10-13 20:24:23.660364] (info) Control channel warning rate: 10
[2019-10-13 20:24:23.660386] (info) Control channel retune limit: 0
[2019-10-13 20:24:23.660408] (info) Frequency format: 0
[2019-10-13 20:24:23.660428] (info) Status as String: false
[2019-10-13 20:24:23.660457] (info) [Onslow P25] Started with Control Channel: 8.537875e+08
[2019-10-13 20:24:23.669205] (info) P25 Trunking - SysNum: 0
[2019-10-13 20:24:23.669269] (info) P25 Trunking Initial Rate: 512000 Resampled Rate: 51200 Initial Decimation: 4 Decimation: 10 System Rate: 48000 ARB Rate: 0.9375
[2019-10-13 20:24:23.669505] (info) P25 Trunking Taps - initial: 311 channel: 1163 ARB: 775 Total: 2249
[2019-10-13 20:24:24.395280] (info) [Onslow P25] Decoding System ID 5DF WACN: BEE00 NAC: 5D1
[2019-10-13 20:24:46.411061] (info) [Onslow P25] TG: 34311 Freq: 8.522875e+08 Not Recording: no source covering Freq
[2019-10-13 20:24:46.936600] (info) [Onslow P25] TG: 34324 Freq: 8.522875e+08 Not Recording: no source covering Freq



and my config.json

{
"sources": [

{
"center": 853500000,
"rate": 2048000.0,
"error": 1000,
"ppm": -2,
"gain": 37,
"digitalRecorders": 4,
"modulation": "qpsk",
"driver": "osmosdr",
"device": "rtl=0"
}
],
"systems": [{
"control_channels": [853787500],
"type": "p25",
"shortName": "Onslow P25",
"recordUnknown": "true",
"autoReturn": 1,
"audioArchive": "true",
"talkgroupsFile": "talkgroups.csv"
}]
}


Any help will be greatly appreciated. At this point I'm not sure what the issue is.

 

[da2ricky]

I was able to get the center freq set and I have MOST transmissions being recorded but I've noticed that some traffic comes in on a channel that's slightly below my "Min Freq" and I'm not quite sure how to adjust this.

With the below config.json I get the following min/max freq:
MAX Freq: 8.541000e+08
Min Freq: 8.517000e+08

I've noticed that every time I see an error of "Not Recording: no source covering Freq", it's coming in on Freq: 851.312500 which is slightly below my min freq.

Raising my rate seems to open up the spectrum, but it starts erroring out before I ever get close to opening up low enough to allow the 851.312500 freq.

{
"sources": [

{
"center": 852900000.0,
"rate": 2400000,
"gain": 30,
"error":1200,
"lnaGain":30,
"digitalRecorders": 4,
"modulation": "qpsk",
"driver": "osmosdr",
"device": "rtl=0"
}
],
"systems": [{
"control_channels": [853787500,853537500],
"type": "p25",
"shortName": "Onslow P25",
"recordUnknown": "true",
"talkgroupsFile": "talkgroups.csv"
}],
"frequencyFormat": "mhz",
"captureDir": "/home/op25/trunk-player/audio_files"
}

HELP!!!!!! lol

 

[boatbod]

If you know the P25 System's lowest and highest frequencies you can calculate the optimal center frequency from F_ctr = (F_lo + F_hi)/2. Hopefully you'll also find that (F_hi - F_lo) < 2400000, otherwise it's just not going to work until you switch to an SDR device with larger sample width.

 

[da2ricky]

If you know the P25 System's lowest and highest frequencies you can calculate the optimal center frequency from F_ctr = (F_lo + F_hi)/2. Hopefully you'll also find that (F_hi - F_lo) < 2400000, otherwise it's just not going to work until you switch to an SDR device with larger sample width.

I actually started dropping the 4th digit of the center freq until I got it within range and it's recording everything loud and clear now. I suppose now that I have the actual formula I can go back and do it properly. Thank you sir!

Now to get rdio-scanner working

 

[boatbod]

I actually started dropping the 4th digit of the center freq until I got it within range and it's recording everything loud and clear now. I suppose now that I have the actual formula I can go back and do it properly. Thank you sir!

Now to get rdio-scanner working

Note that I have over-simplified the sample-width check calculation. In reality you need to account for the bandwidth of the highest and lowest signals as well as any roll-off that occurs at the ends of the sample space. Practically however, as long as the system width fits comfortably inside the maximum sample width you should be good to go.