How to squelch / sensitivity?

[dandud100]

For me it just records noise no matter if i configure 0.0 or 40.2 gain in the config.

Here are three .mp3 for example but i got 100 in like 15 minutes. It is a zip as i can't upload .mp3 rtl-sdr-scanner.zip

So how to prevent this?

[shajen]

In your case frequency 438.250 MHz is probably in use by something. Many different devices (e.g. temperature sensor, camera, garage door) uses it. Please add frequency to ignore in config.json file and try again. There is not squelch to define, rtl-sdr-scanner do it automatically.

Try add this to config:

"ignored_frequencies_ranges": [
    {
      "start": 438200000,
      "stop": 438300000
    },
]

[dandud100]

In your case frequency 438.250 MHz is probably in use by something. Many different devices (e.g. temperature sensor, camera, garage door) uses it. Please add frequency to ignore in config.json file and try again. There is not squelch to define, rtl-sdr-scanner do it automatically.

Try add this to config:

"ignored_frequencies_ranges": [
    {
      "start": 438200000,
      "stop": 438300000
    },
]

Yeah i see that now, because you fixed #1 But it is still not fully functional, see following Screenshots

Screenshot1

Screenshot2

Screenshot3

But it is weird i used the very first public version of your cpp scanner and it does not recorded this stuff.

[shajen]

Interesting. Can you show your config.json file? Please test on the latest version.

[dandud100]

Interesting. Can you show your config.json file? Please test on the latest version.

I use the latest.

My config.json

{
  "scanner_frequencies_ranges": [
    {
      "start": 433075000,
      "stop": 434775000,
      "step": 25000
    },
    {
      "start": 446000000,
      "stop": 446200000,
      "step": 125
    },
    {
      "start": 456840000,
      "stop": 457020000,
      "step": 125
    },
    {
      "start": 457220000,
      "stop": 457400000,
      "step": 125
    },
    {
      "start": 467220000,
      "stop": 467400000,
      "step": 125
    }
  ],
  "ignored_frequencies_ranges": [
    {
      "start": 434400000,
      "stop": 434400000
    }
  ],
  "device": {
    "ppm_error": 0,
    "tuner_gain": 40.2,
    "bandwidth": 2000000
  },
  "recording": {
    "range_scanning_time_ms": 100,
    "max_silence_time_ms": 2000,
    "min_recording_time_ms": 1000,
    "sample_rate": 48000,
    "threads": 4,
    "enabled": true
  },
  "output": {
    "recordings": "sdr/recordings",
    "logs": "sdr/logs",
    "file_log_level": "info",
    "console_log_level": "info"
  },
  "server": {
    "address": "0.0.0.0",
    "port": 9999,
    "key": "",
    "threads": 4
  }
}

[shajen]

I tested it and your config works ok with my rtl-sdr scanner on latest version. The frequencies on your screenshots are different that you posted in config.

[dandud100]

I tested it and your config works ok with my rtl-sdr scanner on latest version. The frequencies on your screenshots are different that you posted in config.

Yeah, you are right, i just found this out in the second you answered. It just does not use my config, if i run it manually it does but with my systemd / systemctl service it does not. What is wrong?

[Unit]
Description=rtl-sdr-scanner

[Service]
User=pi
WorkingDirectory=/home/pi/
Type=exec
ExecStart=/home/pi/rtl-sdr-scanner-cpp/build/auto-sdr config.json
Restart=always
RestartSec=10s
OOMScoreAdjust=-500

[Install]
WantedBy=multi-user.target

Edit: Fixed it by changing following: WorkingDirectory=/home/pi/rtl-sdr-scanner-cpp/

I think you should add a warning to the log that says config.yml not found or so. :)

---

The waterfall thing is still very slow, i dont know if this is normal.

[shajen]

Pass full path to config.json. Probably the path should be like this:

ExecStart=/home/pi/rtl-sdr-scanner-cpp/build/auto-sdr /home/pi/rtl-sdr-scanner-cpp/config.json

[shajen]

It will work slowly, because every switch between frequencies range takes about ~100 ms. So you should definitely choose as few frequency ranges as possible to speed it up.

But if the scanner finds an active frequency, it records it without switching as long as the signal is active.

[Ta-2om]

and the squelch question?

Tried to set max recording time. But no change.

"recording": { "range_scanning_time_ms": 100, "max_silence_time_ms": 4000, "max_recording_time_s": 30, "min_recording_time_ms": 3000, "sample_rate": 48000, "threads": 4, "enabled": true

Thank you

[neonmaus]

ignored_frequencies_ranges

Is this function no longer included in the current version?

[shajen]

@neonmaus

Yes, update to latest version and see below: https://github.com/shajen/rtl-sdr-scanner-cpp#ignored-frequencies

[neonmaus]

@neonmaus

Yes, update to latest version and see below: https://github.com/shajen/rtl-sdr-scanner-cpp#ignored-frequencies

Yeah! thanks for putting it back in :)

[ZL1LAC]

Sorry to be off topic but that's a very interesting Tetra signal.