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expierence with receiver Navilock GNS ADS-B ??

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  • #16
    @Anmer,
    I can not say if SBS-3 is far away, because I do not have tested this receiver.
    Fact is that the GNS5890 has no limitation regarding frame rates as long they are not overlapping.
    As you may know app. 20% of frames are overlapping this is the reason why the GNS5890 has in the middle 20-30% lower frame rate than the beast has.
    Sometimes if we are lucky we have the same high framerate but not stable...reasonly because of lucky moments with only a few overlapping frames.
    but......
    Is this really an indication or more or less a theoretic thing ???
    You can imagine that if we miss two frames in a second because of overlapping we will catch it in the next second.
    So what ? It doesnīt matter.
    At the end of the day the most important thing is to receive all transponders.
    Missing overlapping frames is not a big issue.
    Missing frames which are not overlapping is an issue !
    This is what happend with SDR receivers or with MicroADSB and Radarbox, because of RF design and/or slow decoder firmware.
    Second thing is missing frames because of donought effect (bad RF design or better Gain control)

    What do you think ?

    regards

    Bill

    Comment


    • #17
      G'Day Bill.
      I have my GNS 5890 up & running today, and seen frame rates up to 4900 (depending on traffic of course).
      There may have been higher rates, but I didn't see them.

      There also doesn't appear to be any discernible donut effect that I've heard about. I've had planes flying directly over head today, and visible on screen 100% of the time).
      Range seems to be approx 200NM.

      Regards, Greg.
      GNS 5890 (German), 2 x DVB-T Dongles (China / USA), Mobile One SAN-1090 external base antenna (Australian), Heliax coax (USA).
      HDSDR, Plane Plotter (full version, but not working), adsbScope, Virtual Radar.

      Comment


      • #18
        I assume you mean 4900/min? The Beast can do 4900/sec.

        As you are aware RTL1090 software can handle DVB-T dongles easily. With proper gain settings you can expect 1/3 of the Beast data rate (benchmarked by F5ANN), which is not too bad.

        ADS-B (you mean Mode-S) is not PWM but PPM. To decode PPM there is no PLL needed (for what?). The dongles data rate is limited by the USB channel and the PC processing speed of samples, nothing else.

        I am surprised...

        Mike: I would suggest that hardware sales persons should not be allowed to talk badly about competitors here.

        Thanks
        Andy
        jetvision.de

        Comment


        • #19
          G'Day Andy.
          Yes, you are correct, the highest frame rate I had seen at the time was 4900 per Minute.
          This has now increased to 6700 / min (observed).

          I'm a newbie, so I don't really know if the above figures are good, bad or irrelevant.

          I believe Bill was trying to explain why a DVB-T Dongle, with decoding software running on a PC was going to be slow - although to be honest, I don't really understand either his response, or your comments to him.
          I need an explanation in laymans terms ! ;-)
          Please read my 'ignorance is bliss msg 4 or 5 msgs up, & see if you can explain it to me.

          My DVB-T dongles still haven't arrived yet, so in preparation, I am now on your website examining the RTL1090 software you mentioned.

          Also, I believe the GNS 5890 does not have what they call 'expensive' FPGA ? circuitry (whatever that is).
          Whereas the Beast does have it, and I assume this is why it costs more than my Laptop !

          However, that doesn't mean I won't buy a Beast as well... After watching a series of videos on YouTube, it doesn't appear to be as difficult to build as I first imagined.
          Indeed just 2 days ago I went out and bought a more powerful soldering iron, some flux, and solder - in preparation for purchasing a Beast. BUT...

          If, as Bill implies, I'm receiving 'enough' data to display a decent amount of tracking / aircraft movement using the GNS, then maybe a Beast isn't required.

          The reason I bought the GNS was totally because of the price, not based on the framerate.

          Regards, Greg.
          (A user, with no vested interests)
          Last edited by GregHudson; 2012-12-05, 23:11.
          GNS 5890 (German), 2 x DVB-T Dongles (China / USA), Mobile One SAN-1090 external base antenna (Australian), Heliax coax (USA).
          HDSDR, Plane Plotter (full version, but not working), adsbScope, Virtual Radar.

          Comment


          • #20
            Depends on your target rates really. Beast is good in EU/UK where there are 200 or so contacts at one time. Whereas here and aus where you may only get 20-30 it could be fine to use a lower model decoder.
            Posts not to be taken as official support representation - Just a helpful uploader who tinkers

            Comment


            • #21
              Originally posted by Oblivian View Post
              Depends on your target rates really. Beast is good in EU/UK where there are 200 or so contacts at one time. Whereas here and aus where you may only get 20-30 it could be fine to use a lower model decoder.
              G'Day Oblivian.
              You have a good point there. Maybe upgrading from a GNS 5890 to a Beast isn't necessary if there's no benefit to me (i.e. more aircraft visible, over a longer range) or better (if any) sensitivity.

              How have you been going with your DVB-T dongle testing ?

              Regards, Greg.
              GNS 5890 (German), 2 x DVB-T Dongles (China / USA), Mobile One SAN-1090 external base antenna (Australian), Heliax coax (USA).
              HDSDR, Plane Plotter (full version, but not working), adsbScope, Virtual Radar.

              Comment


              • #22
                Uuuh not me said the flea. I only got as far as research, not actually getting one to try
                Posts not to be taken as official support representation - Just a helpful uploader who tinkers

                Comment


                • #23
                  @junglejet
                  mmmhhh Andy....what you are doing ?
                  I believe itīs absolutly correct to inform members about receivers and why not make a comparison ?
                  Comparison should be fair mean one Antenna a splitter and then input into the ADS-B receivers.
                  If you are talking about 4900/min and compare with the Beast in such kind this is not fair because you do not
                  know what was happened in the air :-) Maybe there was only 4900f/min available who knows.
                  In a thread above I have explained that the GNS 5890 has nearly unlimited framerate means it works till 168.000f/min =2800f/s
                  You will never see such kind of framerate worldwide. So we are talking about theoretical things and not real world.
                  So I believe from this side of view we are fine.
                  Ok....
                  so what is the different between first we have to compare between receiver technologies
                  There are DVB-T Dongles on the market using Realtek chip RTL1090 or Elonics chip E4000
                  This technology are so called Software defined Radios SDR. We canīt use such kind of Radios for ADS-B
                  You will receive maybe 4-5 f/min thats all and you will miss a lot of frames reasonely that this kind of receivers are using a so called PLL which is too slow.
                  So for FR24 itīs a bad idea to feed data from this kind of receivers
                  They will make a lot of traffic and there are large gaps between receiving first ADS-B position and the next ADS-Position
                  Hopefully I have explain and you understand my meaning.
                  Aaaaarg I see you underline and checked you website.....you have a shop selling such kind of receivers ....now I understand your issue because
                  of comparison ....
                  Ok I fully agree itīs not nice if I had a shop that there is a company announcing another technology .....
                  So I fully understand your position of claiming.
                  But .... let me point out you are claiming and you are talking about a receiver you did not have actual tested and you are selling SDR receivers
                  which are used for ADS-B receiption knowing that they will loose 90% of frames.
                  Hopefully not for use streaming data into FR24 .....that will be definitely a bad idea.

                  Ok to be honest sure I will stop here because of such kind of situation. My first interest is to show the members
                  what are the best ADS-B receiver technologies right now. And I believe that some members do not want to hear that.
                  We have developed our receiver as technical enthusiasts to optimize technology and to realize the theoretical things we have in mind regarding ADS-B receivers.
                  During one year developing we designed the best possible receiver technology based on non FPGA so we are very near on the limits which are possible by using a non FPGA CPU.....and we want to show that also some people are not right talking about non FPGA receivers.....they will loose frames because of CPU speed.
                  We want show that it is possible and that the CPU is fast enough...... not only theoretical we want it see in real.
                  I will invite you to test the GNS 5890 ... I just have done it against nearly every receiver (not SBS-3 but I will do soon)
                  And you are correct the Beast is the reference for me. Some threads above I explain why ...
                  There are also reasons to use the Beast ...If you want to have more range or if you need really to decode every plane in a second
                  If you can live with a smaller range 300km and with some gaps because of overlapping frames our technology
                  is the best value you can get for this price.

                  I will invite you to test send me a message to info(at) gns-gmbh.com and I will send you our receiver for testing.
                  So we are talking about real comparison and not about advertising...and hopefully you will post your impression about.

                  Deal ? ;-)

                  regards
                  Bill
                  Last edited by Bill2002; 2012-12-06, 06:59.

                  Comment


                  • #24
                    Originally posted by Bill2002 View Post
                    Comparison should be fair mean one Antenna a splitter and then input into the ADS-B receivers.
                    Not too easy as the GNS5890 has a non-standard, MCXantenna connector. Three weeks delivery from China. As soon as I get mine I will do a comparative test.

                    Originally posted by Bill2002 View Post
                    This technology are so called Software defined Radios SDR. We canīt use such kind of Radios for ADS-B
                    Totally incorrect statement. See:

                    http://radarspotting.com/forum/index...ic,1697.0.html

                    Whilst I still think a specialist Mode-S receiver is a better solution for most peaople, a DVB-T USB device and SDR can be used for "ADS-B".

                    Originally posted by Bill2002 View Post
                    I will invite you to test the GNS 5890 ... I just have done it against nearly every receiver (not SBS-3 but I will do soon)
                    Hmmm? Why have you not tested your receiver against the the best, market leading product?

                    For the record, I'm not working for nor do I have any interest in promoting the products of any one manufacturer.
                    Mike


                    www.radarspotting.com

                    Radarspotting since 2005

                    Comment


                    • #25
                      Anmer,

                      first the MCX adaptor we are using is a standard adaptor. May be its not actual your standard.
                      By the way I am buying a lot of stuff in ASIA. Three weeks delivery time.....is it delivered by feet ?
                      With DHL or UPS standard is 1 week

                      ....go to AMAZON and search "MCX SMA" you will find a lot for what ever 9 bucks within 4 days or faster.

                      Totally incorrect statement ? Why ?
                      I am working since years in tuner design. Also I have developed DVB-T tuners based on Elonics 4000 and Realtek designs.
                      You can trust me...what I am talking about.
                      The point is that you have linked a webpage ... but you do not explain how they get a higher framerate ;-)
                      "After some experiments with antennas and lashing up a pre-amp" they get a framerate of about 73f/s.
                      I donīt want to say thats a bad result for SDR based receiver itīs really the best ADS-B performance I had seen before.
                      But my point of view: if there are app. 1000f/s in the air region Newcastle (England) and you catch 73f/s loosing 93% is this bad or is this good ?


                      To get this framerate you have to add a pre- amp and a maybe 10dB antenna on a very good place to get a framerate which is low end.

                      regards

                      Bill

                      Comment


                      • #26
                        The MCX is your standard. All the other Mode-S receivers I have are either BNC or SMA.

                        Perhaps you should supply a free adapter?

                        Your statement read:

                        "This technology are so called Software defined Radios SDR. We canīt use such kind of Radios for ADS-B "

                        That's "totally incorrect".

                        Forget all the frame rate counts. What really matters is the number of aircraft tracked by the different receivers.

                        Believe me, I know what I'm taking about too.

                        And I'm not posting here to promotet my product.
                        Mike


                        www.radarspotting.com

                        Radarspotting since 2005

                        Comment


                        • #27
                          To make it clear for the innocents here:

                          A DVB-T dongle is not used as a typical SDR radio to receive Mode-S signals, but as a A/D converter with USB interface only. Therefore there is no basic difference in the frontend to any other receiver design.

                          No, I forgot, it has a 7-bit A/D converter that is more powerful than a comparator as a signal detector.

                          Then there is an individual thread on the PC that does what the FPGA does in the better devices.

                          The only other difference is sample rate, which is lower for the dongles, because the USB line is not faster.

                          Entertaining....

                          vocare argentum, tacere aurum est

                          Comment


                          • #28
                            @ANMER
                            I have to apologize that I didnīt explain clear enough
                            SDR Radio is state of the art for high quality ADS-B receiver.
                            USB SDR Dongles are not my recommendation (technical reasons low framerate)
                            So I was not exact enough therefor incorrect

                            Frame counts are in direct correlation to tracked aircrafts plus minus a few %.
                            Framerate 73f/s I have seen from DVB-T Stick was the Mode/S framerate so the real ADS-B framerate which also contents position is less. (DF17,18,19)
                            The ADS-B position update rate is between 1 to 5 times/s depend on different things.

                            approx....number of tracked aircrafts = (frame rate) /(average positioning update rate)

                            So maybe I misunderstood you because of the meaning that aircraft which are tracked are really matter
                            ...maybe I am wrong please explain
                            I do not want to write something wrong here.

                            I would like to stop this discussion here title of the thread is "expierence with receiver Navilock GNS ADS-B ??"
                            Now we are writing about technical things and i believe that we will dive more and more in ADS-B stuff like frames meaning of frames ect.

                            By the way Mike www.radarspotting.com is this promotion ? Or I am wrong ?

                            @junglejet
                            I am a little bit out of the USB Stick design but I remember that the Elonics tuner chip was weak on 1090 MHz (also out of spec.)
                            So I believe that the USB SDR stick is tuned to 1090MHz and the audio is captured by PC via the USB something like that.
                            So the signal detection is complete made on the PC by decoding the audio stream ...that is what I imagine.
                            So because of that there is a high traffic stream on the USB port and limited framerate. For that 73f/s ModeS is not a bad result but for ADS-B as a virtuell radar really to low. Maybe 73f/s is because of USB3.0 ?
                            It would be better to use the decoder chip directly for ADS-B ....


                            regards Bill
                            Last edited by Bill2002; 2012-12-07, 16:17.

                            Comment


                            • #29
                              Originally posted by Bill2002 View Post
                              By the way Mike www.radarspotting.com is this promotion ? Or I am wrong ?
                              I'll let the readers decide. But in my opinion it's not promoting anything other than a comprehensive message thread with examples of DVB-T dongles being used to plot ADS-B traffic.

                              And since my forum is free to use and doesn't generate income from advertising, I think that link was relevant to this topic.

                              Whereas you're posting here to promote the GNS5890 product and generate income.

                              And as soon as my connector is delivered by pack horse I'll run a comparative test and publish the results for all to see.
                              Mike


                              www.radarspotting.com

                              Radarspotting since 2005

                              Comment


                              • #30
                                Anmer,

                                to be honest you should compare SBS-3 vs. GNS 5890 both with the newest firmware/hardware.
                                If you do not have Ver.3.0 or Ver4.0 which is now coming around the corner send me an email info@gns-gmbh.com
                                I will send you the newest ADS-B stick as a free test sample ;-).
                                i have seen a contest between both in another forum Plane Plotter running
                                SBS-3 with discone GNS 5890 rod antenna (which is included) based near Munich
                                Same time:
                                SBS-3 13000 f/s
                                microADS-B 1500f/s

                                GNS 5890 rod antenna (which is included in the package) based near FFT
                                GNS 5890 V3.0 13000 f/s

                                May be because of traffic situation there is a difference on the other point discone on the roof against small rod antenna out of the window
                                I am interested in the result you will get. I will also make also a comparison which will be completely documented on youtube
                                that every one is able to follow the steps and understand the result. By the way we are working on a new firmware which will increase again the performance.
                                But there are only small steps. Not such big steps like between Ver.2.0 and Ver. 3.0
                                If you have a GNS5890 Ver3.0 the firmware can be updated to Ver4.0 in an easy way by yourself. Below V3.0 itīs not possible
                                to flash a new Firmware because of different hardware designs.

                                Again I give information about our product and help to support
                                ....the thread title is expierence with receiver Navilock GNS ADS-B ??
                                I believe it is very helpful for every one to know that we are willing to support members here in the forum.
                                I also believe that I can help forum members to get a clear view about the situation on the ADS-B market.
                                Our ADS-B equipment is also selected by professional B2B customers which are using our ADS-B technology (modules) in mobile aircrafts navigation equipment and we have also transmitters for ground vehicles.
                                So I will be stay tuned waiting for your comparison results.
                                I will also prepare something and test the SBS-3 with simulated ADS-B data and real world data vs. GNS 5890.
                                I hope that we both will have the same results ;-)

                                My forecast ....between both receivers there will be a small difference may be 10% difference normally the SBS-3 must be better
                                regarding range and framerate. On the other point the RF parts are different... So actual I canīt say which receiver will perform better.
                                We will see ....

                                regards

                                Bill
                                Last edited by Bill2002; 2012-12-07, 23:23.

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