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  • Here's an update. I had my RPis up in the attic in a fireproof steel box. All the power supplies were in there too. It looked nice but I never thought it would withstand the heat up there. Having done some testing and playing around up there I have now put in a 50 Ohm feeder that's 25-feet long, kept a powered 10dB gain LNA and 1090 MHz filter in the attic and have moved the RPi down to my workshop one floor below. There was no discernible difference in performance. I have disconnected T-KCLT19 forever and have now learned enough of the software to build a test system that just has dump1090-mutability on it.

    My site now feeds both FR24 and FA. I used the script that abcd567 posted and it has worked well several times. Today T-KCLT3 is now number two in CLT on FR24 and is number 2 in CLT on FA on both counts aircraft seen and positions. I still use my original - the first one I built - 8 element CoCo. I have never built one better. I just got lucky I guess.

    Thank you for all your help.
    Untitled.jpg
    T-KCLT3 - Raspberry Pi3 Jessie, 8 element collinear indoor antenna

    Comment


    • Hi everyone, im using a rtl sdr and i live about 15miles from the airport, can anyone recommend a good antenna also i live under a busy stretch of flight path. i want to listen to air traffic etc.
      many thanks
      Last edited by sdcserg; 2017-04-07, 14:29.

      Comment


      • Welcome. I have not been doing this for very long either. I have however had quite a bit of experience with antennas and telecommunications in my past professional life.

        The short answer to your question is that there is no best antenna in the sense that one size fits all comers. There are however some fairly simple basic rules for antennas and their placement or installation.
        - If you can put your antenna outside.
        - Put your antenna so that as far as possible it has a high and clear view of the entire sky.
        - Keep the cable running between your antenna and receiver under about 30 feet.

        The above said, you can now look at the antenna itself. In this very thread there are some simple and some very technical posts on home antenna construction. If you are able and have the time look at posts and Google searches on the construction of Franklin antennas and of coaxial collinear (CoCo) antennas. I use an 8 element CoCO that I made myself following details in this thread. My first one worked really well and all others have performed less well. My Franklin antenna worked OK-ish but not as well as the CoCo. Bear in mind that these are just my own experiences.

        If you do not want to build an antenna there are several purchase options.

        https://www.amazon.com/1090MHz-ADS-B...+ads-b+antenna

        http://www.ebay.com/itm/Antenna-ads-...GqN-3NOXaZFQcw

        http://www.dpdproductions.com/page_vhf_air.html#adsbout

        All this, of course depends on how much you wish to spend. I recommend that you Google and read reviews on any antenna you are considering before you buy in order to avoid buyers remorse.

        Lastly please look at abcd567's excellent post on making and modifying antennas http://discussions.flightaware.com/post168941.html

        ADS-B reception is, on the surface, very simply. The more you get into it, the more you want and the more complicated (in my case fascinating) it becomes.

        I hope you enjoy your new hobby as much as I am doing. Please continue to post your experiences as there are many people here who will help you and many others who are also starting and are looking at similar issues to you. Finally, do not be afraid to ask for help. Most of use have fallen down our own potholes and have broken our own fingernails getting out. That's one way we learn.
        T-KCLT3 - Raspberry Pi3 Jessie, 8 element collinear indoor antenna

        Comment


        • Originally posted by rederikus View Post
          Welcome. I have not been doing this for very long either. I have however had quite a bit of experience with antennas and telecommunications in my past professional life.

          The short answer to your question is that there is no best antenna in the sense that one size fits all comers. There are however some fairly simple basic rules for antennas and their placement or installation.
          - If you can put your antenna outside.
          - Put your antenna so that as far as possible it has a high and clear view of the entire sky.
          - Keep the cable running between your antenna and receiver under about 30 feet.

          The above said, you can now look at the antenna itself. In this very thread there are some simple and some very technical posts on home antenna construction. If you are able and have the time look at posts and Google searches on the construction of Franklin antennas and of coaxial collinear (CoCo) antennas. I use an 8 element CoCO that I made myself following details in this thread. My first one worked really well and all others have performed less well. My Franklin antenna worked OK-ish but not as well as the CoCo. Bear in mind that these are just my own experiences.

          If you do not want to build an antenna there are several purchase options.

          All this, of course depends on how much you wish to spend. I recommend that you Google and read reviews on any antenna you are considering before you buy in order to avoid buyers remorse.

          Lastly please look at abcd567's excellent post on making and modifying antennas

          ADS-B reception is, on the surface, very simply. The more you get into it, the more you want and the more complicated (in my case fascinating) it becomes.

          I hope you enjoy your new hobby as much as I am doing. Please continue to post your experiences as there are many people here who will help you and many others who are also starting and are looking at similar issues to you. Finally, do not be afraid to ask for help. Most of use have fallen down our own potholes and have broken our own fingernails getting out. That's one way we learn.
          Hi and thank you very much for the informative reply, yes i can put it outside by my sky dish tha is near the roof, and yes the cable would be very short,
          i can spend around 70 on a antenna.
          im new to this so see how it goes :-)
          thank you.

          Comment


          • thanks for that very helpful, will i still be able to tune to air traffic tower etc?

            and to add yes antenna will be outside, i live on the top of hill no obstructions.
            Last edited by sdcserg; 2017-04-08, 14:27.

            Comment


            • Originally posted by sdcserg View Post
              thanks for that very helpful, will i still be able to tune to air traffic tower etc?

              and to add yes antenna will be outside, i live on the top of hill no obstructions.
              You will still be able to tune to the tower - but as the antenna is not designed for those frequencies, signals will be much lower... in fact marginal signals wont be heard at all.
              Having said that, I use my 1090 coco and still receive local 2 Metre signals, so give it a go !

              Comment


              • Originally posted by Rooster View Post
                You will still be able to tune to the tower - but as the antenna is not designed for those frequencies, signals will be much lower... in fact marginal signals wont be heard at all.
                Having said that, I use my 1090 coco and still receive local 2 Metre signals, so give it a go !
                thanks, i do have a good 1090 sorted, and like you say ATC is a no go at the moment so any good recommendations would be much appreciated :-)

                Comment


                • Originally posted by sdcserg View Post
                  thanks, i do have a good 1090 sorted, and like you say ATC is a no go at the moment so any good recommendations would be much appreciated :-)
                  It's not so easy without knowing where you are, antennas are expensive to ship. US ? UK ?

                  Google "vhf airband antenna" and I'm sure you will get results.

                  I can recommend Procom and AC-Marine in Denmark.

                  /M
                  F-ESDF1, F-ESGG1, F-ESGP1, F-ESNK1, F-ESNV2, F-ESNV3 F-ESSL4, F-LFMN3
                  P-ESGR, P-ESIA, P-ESIB, P-ESGF
                  mrmac (a) fastest.cc

                  Comment


                  • Originally posted by MrMac View Post
                    It's not so easy without knowing where you are, antennas are expensive to ship. US ? UK ?

                    Google "vhf airband antenna" and I'm sure you will get results.

                    I can recommend Procom and AC-Marine in Denmark.

                    /M
                    hi thanks for the reply im in the uk

                    Comment


                    • Originally posted by sdcserg View Post
                      hi thanks for the reply im in the uk
                      Something like this should be useful. (But I have no personal experience with this particular antenna.)

                      http://www.moonraker.eu/scanning-and...eiving-antenna

                      /M
                      F-ESDF1, F-ESGG1, F-ESGP1, F-ESNK1, F-ESNV2, F-ESNV3 F-ESSL4, F-LFMN3
                      P-ESGR, P-ESIA, P-ESIB, P-ESGF
                      mrmac (a) fastest.cc

                      Comment


                      • I have a few months ago been selected to host a FR24 box(F-KENL1). Since then I have been experimenting with other antennas and playing around with a flightaware dongle on a raspberry pi using Piaware.

                        I have made three coco antennas recently. all using TFC-T10 RG11 tri shield coax with 85% VF

                        an 8 element (7 plus top that is 1/4 / 1/4 stinger that shorted) (116.75mm)
                        12 element same thing
                        8 element with the other calculation in this thread that used a longer wavelength for 1/2 wave (maybe 124 or 126mm)

                        Using the FR24 antenna as a base plot, I got these

                        FR24 - 450 msg/sec, 240 miles -79 ac tracked
                        8 element 116.75mm -420 msg/sec, 240 miles, 91 ac tracked,
                        8 element with longer wavelength - 350 msg/sec, 170 miles, 81 ac tracked
                        12 element 116.75 - 370 msg/sec, 210 miles, 87 ac tracked (maybe not tracking good right overhead since higher gain)

                        NOTE - the FR24 is 5ft higher then the rest of the coco antennas since it has the best spot on the mast to mount it so it can see better over the pole barn in the next lot to the north. Every other direction has trees so north is the best direction I receive from

                        Dont have any better measurements, but thats the best I have without nice test equipment. Not using a preamp or any sort of tuning adjustment, just rg6 30ft length straight to the flightaware dongle.

                        Comment


                        • I've got a weird issue. My antenna is on a tower on a remote hilltop at 1400 feet, it's all solar powered and wifi linked. The tower is a wind up and goes from 20 foot to 50 foot. Over the past couple of years several times I have wound the tower up to try to get more range from my FR24 box. The FR24 antenna has pride of place on top of the tower. This is the weird thing ... when I wind the tower up .. every time I drop about 10 - 20 miles in range ! I normally get 200-205 miles max range with the tower down... when I wind it up I get only get 180 -190nm. I have tried different coax, including LD4-50 Heliax and even at one time I mounted the FR24 box at the top of the tower with just a couple of meter of coax. Always the same .. less range with height .. its not coax loss.

                          What could it be ? There is a commercial tower about 200 feet away but it is over 300 feet high, I can't imagine that I am getting up into its signals and anyway I believe everything on that tower operates at 2.1 Ghz which should not hurt 1 Ghz. There are mobile phone towers about 3 kms away but when I put another receiver on the antenna and listen to 1090 I don't hear any interference. My only other thought is that with the extra height the angle of radiation is dropping down to the horizon where there are mountains in all directions.

                          Anyway I have a low noise amp on the way and will add that to the system and keep playing ... it has a highpass filter so that might help if it is interference.

                          Comment


                          • F-YMEN3
                            If you are going to use filter, use band-pass filter. Narrower the band, better the filtering.

                            There are many types of band-pass filters such as Cavity Filter, Ceramic Filter, SAW filter, LC filter, and Stub filter.
                            Last edited by abcd567; 2017-05-02, 02:21.

                            Comment


                            • Actually it is a band pass, SAW filter, my mistake.

                              Comment


                              • If there is suspicion of interference, which is definitely a risk in your location, try a narrow cavity filter first. Absolutely no amp/lna, regardless of if it comes with some kind of filter or not. a Good cavity has under 1 dB of insertion loss, much better than a SAW and you can live with that. Don't add more active equipment.

                                /M
                                F-ESDF1, F-ESGG1, F-ESGP1, F-ESNK1, F-ESNV2, F-ESNV3 F-ESSL4, F-LFMN3
                                P-ESGR, P-ESIA, P-ESIB, P-ESGF
                                mrmac (a) fastest.cc

                                Comment

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