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Sudden Loss of Reception Range

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  • Sudden Loss of Reception Range

    Over the last day i have suffered a sudden loss of receiver range, going from around 190+ miles to only receiving signals that are almost line of sight.

    I have tried a reboot then ran sudo bash -c "$(wget -nv -O -"
    and this was the output;

    Found 1 device(s):
    0: Realtek, RTL2832U, SN: 00001000

    Using device 0: Generic RTL2832U
    Found Rafael Micro R820T tuner
    Supported gain values (29): 0.0 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 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
    [R82XX] PLL not locked!
    Sampling at 2400000 S/s.

    Info: This tool will continuously read from the device, and report if
    samples get lost. If you observe no further output, everything is fine.

    Reading samples in async mode...
    Allocating 15 zero-copy buffers
    lost at least 4 bytes
    Signal caught, exiting!

    User cancel, exiting...
    Samples per million lost (minimum): 0
    Test finished!
    More than 2 lost samples per million or other errors probably mean the receiver isn't working correctly.
    Try another power supply before condemning the receiver though!
    No undervoltage detected, looking fine!
    If the dongle is not directly plugged into the Raspberry Pi, lack of power/voltage could still be an issue.
    Even without detected undervoltage a better power supply can often improve reception!
    For optimum performance i would recommend the Official Raspberry Pi power supply.

    I then ran sudo systemctl status dump-fa -I

    sudo systemctl status dump1090-fa -l
    ● dump1090-fa.service - dump1090 ADS-B receiver (FlightAware customization)
    Loaded: loaded (/lib/systemd/system/dump1090-fa.service; enabled; vendor preset: enabled)
    Active: active (running) since Wed 2020-05-13 15:42:08 BST; 7min ago
    Main PID: 5297 (dump1090-fa)
    Tasks: 3 (limit: 2200)
    Memory: 4.3M
    CGroup: /system.slice/dump1090-fa.service
    └─5297 /usr/bin/dump1090-fa --device-index 0 --gain -10 --ppm 0 --lat 56.61 --lon -2.81 --max-range 360 --net --net-heartbeat 60 --net-ro-size 1300 --net-ro-

    May 13 15:42:08 raspberrypi systemd[1]: Started dump1090 ADS-B receiver (FlightAware customization).
    May 13 15:42:08 raspberrypi dump1090-fa[5297]: Wed May 13 15:42:08 2020 BST dump1090-fa 3.8.1 starting up.
    May 13 15:42:08 raspberrypi dump1090-fa[5297]: rtlsdr: using device #0: Generic RTL2832U (Realtek, RTL2832U, SN 00001000)
    May 13 15:42:08 raspberrypi dump1090-fa[5297]: Found Rafael Micro R820T tuner
    May 13 15:42:08 raspberrypi dump1090-fa[5297]: rtlsdr: enabling tuner AGC
    May 13 15:42:08 raspberrypi dump1090-fa[5297]: Allocating 4 zero-copy buffers

    I have attached two screenshots of receiver range and signal output from Graphs1090 and my gut feeling is there is perhaps a hardware issue?

    Traffic volumes have certainly dropped, but it appears the receiver range has dropped to line of sight.

    The hardware is around 5 years old and whilst it's not run 24/7, it's on a lot. The small FlightAware amber light on the dongle no longer works etc.

    RSSI ratings are rarely below -15, where they would often within single figures, close to 0.

    And advice wold be greatly appreciated.
    Last edited by Graeme2812; 2020-05-13, 15:06.