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rpi - no aircrafts tracked

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  • rpi - no aircrafts tracked

    Hi everyone,
    I've installed all the software however I've been having some issues with capturing real aircraft.
    Through the performance graphs it appears some messages are caught but nothing happens..

    The dongle is a Nooelec E4000, with attached antenna.
    Raspi 3B+

    Lead me to find out how to fix this?

    I wanted to post links to the performance graphs, but I am not yet able since I came straight to find out how to share :P

  • #2
    The E4000 isn't really good on 1090 MHz i believe.
    But it should work.

    Check this thread: https://forum.flightradar24.com/thre...h-DVB-T-Dongle

    Are you by chance using the Nooelec 1090 MHz antenna?
    It's really really bad, use another one.

    Just putting a 7 cm piece of wire and plugging it into the SMA connector of a dongle provides much better results than the Nooelec antenna.
    You can open the plastic case of the Nooelec antenna and see what it looks like inside.
    Last edited by wiedehopf; 2019-08-17, 11:43.

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    • #3
      I wasn't expecting to get the best sensitivity ever, or even longest range.
      Just thought an airplane I could see in naked eye on top of me would appear as sent data. hahah

      I am using what appears to be an embedded antenna, since it looks attached to the dongle.
      It is a black dongle and I could measure the antenna size to see what frequency is it tuned to.

      Could eventually also open the nooelec dongle to see if there's a hidden sma or something.

      Comment


      • #4
        The antenna should have a screw connector, that's SMA.

        If it's the NooElec antenna, then that's the reason for your problems.
        Unscrew it, put in a 7cm piece of wire and it should be better.

        The antenna also needs to be pointed straight up to receive aircraft properly.
        (Just stand the RPi up )

        See this picture:
        https://www.nooelec.com/store/sdr/sd...ndle-5dbi.html

        These antennas are crap and not made for ADS-B.
        No clue what nooelec is thinking even saying high gain, it's just wrong.

        But you can see the bottom part with the roughing, that's the part that can be turned to unscrew the antenna.
        or just twist the whole antenna to unscrew it.
        Last edited by wiedehopf; 2019-08-17, 11:52.

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        • #5
          You were right, I was able to detach the antenna.
          It wasn't SMA I think, since it didn't need screw/unscrew just pulling it out.

          Also, the antenna is one of those telescopic that you can extend.
          And it is/was pointing up.
          Should it be 7cm or 27cm? I thought 7cm is for 4280MHz. Maybe I'm missing something ?

          Comment


          • #6
            7 cm.

            https://www.electronics-notes.com/ar...e-vertical.php
            https://en.wikipedia.org/wiki/Monopole_antenna

            Telescopic antenna, can you adjust it to 6.5 cm?
            Including some radials won't hurt, they need to be connected to ground though.

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            • #7
              The best antenna has a length of exactly 69 mm.
              There are a couple of DIY instructions here in the forum.

              Give it a try it will be a massive increase.

              Comment


              • #8
                My knowledge of antennas is not very big.
                Alright, I see it's quarter wavelenght.
                The shortest it goes is about 8-9cm, which I just did. Perhaps it helps ?
                If not I guess I'll have to order a different antenna.

                After this post I'll just attach the previous performance figures.
                Though even with a bad antenna I thought I would be able to find and send some airplanes.

                Comment


                • #9
                  Check the forum for a DIY antenna.
                  Good improvement already with little improvement

                  I bought the Stick with a little indoor antenna, removed the pin and replaced it with a peace of copper wire on exactly the required length.
                  This has been replaced today by a first spider which took me another 20 minutes to build for almost zero money

                  Comment


                  • #10
                    Originally posted by magnum View Post
                    Check the forum for a DIY antenna.
                    Good improvement already with little improvement

                    I bought the Stick with a little indoor antenna, removed the pin and replaced it with a peace of copper wire on exactly the required length.
                    This has been replaced today by a first spider which took me another 20 minutes to build for almost zero money
                    hahah.
                    Fair enough. I might as well see what I could do.
                    Maybe I can find a piece of copper and cut the said 6.5~7cm

                    Edit: The shortening of the telescopic didn't appear so give any positive effect...
                    Unfortunately my previous post with performance figures has to be approved by an admin before it's accepted, anyhow soon we could discuss if it really is antenna/dongle fault.
                    Last edited by T-LPCO39; 2019-08-17, 14:11.

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                    • #11
                      These are the dongle and antenna: https://www.nooelec.com/store/nesdr-...32u-e4000.html
                      Performance:


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                      • #12
                        Sure, it's not only the antenna. The whole setup must fit.

                        And it depends on your environment.

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                        • #13
                          With that antenna, i'd say the antenna is the problem.

                          You can try extending it to 13 cm and see if that helps.
                          Most likely it doesn't.

                          If you are not using it for anything else you can just cut it at 6.7 cm

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                          • #14
                            I guess it really was antenna+dongle all along.
                            I tested with an RTLSDR blog v3 and immediately started finding airplanes!
                            In the first minutes after reboot, 3 airplanes in a 20nm radius.

                            I guess I must order another dongle since I used this blog v3 to remote monitoring other frequencies.

                            Comment


                            • #15
                              See these recommendations:
                              https://github.com/wiedehopf/adsb-wi...s-for-purchase

                              If you don't want an external LNA, getting a stick with internal LNA and filter for 1090 MHz is very nice for reception.

                              (Flightaware ProStickPlus or Radarbox green FlightStick)

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