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Phantom Transmission

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  • Phantom Transmission

    For a few weeks now I have TXLU01 always there on my DUMP1090, showing as on the ground but no position and occasionally showing a squawk but I am nowhere near any airport, nearest is over 20Km and certainly not line of sight due to terrain, lose any landing aircraft at about 700ft.

    The signal strength normally ranges from -19 to -22dbfs but at present has dropped about 3-4db possibly due to precipitation in the air, I was wondering if it may be a transponder under soak test but I would have thought they would have run it into dummy load if it was under test and as far as I know there are no places near me that would be repairing these units.

    anyone have any idea as to what this signal maybe?

  • #2

    They seem to do what they please

    342345 is the hex it's been associated with in past. But without the HEX you are seeing hard to know, as txlu01 is what is being likely sent/input into the device (or your dump1090 is doing a lookup and associating it with it). But the HEX identifies it. The raw data is what's needed. Not what the dump1090 map displays.
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers


    • #3

      Thanks for the reply.

      HEX = c87ee8

      From my DUMP1090...


      Spain? highly unlikely...
      My coverage area:
      Coverage area.png

      Not forgetting the extent of my coverage area will be planes flying at well above FL300. so unless someone in Spain has a transponder in a tethered blimp pumping out megawatts ERP, definitely closer to home, definitely an RF source as I was able to reduce the RSSI by 3dbfs by using a splitter as an attenuator.

      Just googled the hex, seems it is a ground station, Showing up on a FlightAware site not too far from me.
      Last edited by Basil B; 2020-07-03, 06:58.


      • #4
        That's a new zealand hex.. (where I am) and we sure don't run callsigns like that.

        So it's almost certainly noise/bad decodes from something else

        There is a hit for it for a bad transponder on an east midlands ground station here (Bardon Hill)

        And falsely over Poland.
        Posts not to be taken as official support representation - Just a helpful uploader who tinkers


        • #5
          I think that are ground-vehicles or something from the infrastructure of an Airport. I have similar receptions.
          I live near the BER Airport 9km/5,7miles distance.
          For a long time I thought it was ground vehicles from Berlin Tegel Airport IATA: "TXL". But TXL and SXF closed down and "BER" opened last year. And I continue to receive vehicles with TXLU identification.

          And it doesn't matter with which Software you decode the data. FlightRadar, ADSBScope, DUMP1090, SkyAware. The ident will be the same.

          The T600 is definitly a groundvehicle. I receive several TXLU and ERARMTR here around the clock.
          This pic shows the reception around 1:35AM

          Update: Poland/Warsaw Airport:

          Attached Files
          Last edited by MillerBerlin; 2021-02-20, 15:31.
          EDDI90 | RaspberryPi3B, Nooelec NESDR SMArt, homemade 7Element Collinear Antenna.