Announcement

Collapse
No announcement yet.

best antenna

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Originally posted by DavidH View Post
    I never gave it thought, I have built 3 and I can confirm its not the way to go, planes went down from 80+ to 40, messages went down from 600+ to 500, but all these bits of bent wire have there own personality, I lose aircraft landing at Gatwick around 2500 ft but with the quad I can see them down to 1200 ft. One steep forward two steps back, the only problem is the steps back are bigger then the steps forward, I did try one with the twist taken out so the elements were vertical but that wasn't any good either.

    Well not one to be beaten I'm trying a bicone at the moment and early indications are it just has the edge over the jpole.

    [ATTACH=CONFIG]8067[/ATTACH]


    Dave
    Have you tried a 1/4 wavelength Ground Plane like Spider or Cantenna? These are easy & sure antennas, and serve as good refrence /benchmark for evaluating various antennas you make. Have a look here:

    3 EASY ANTENNAS FOR BEGINNERS

    .
    .

    Comment


    • Hi abcd yes I have a 1/2 wave dipole, to be honest is hard to improve on it, my antenna is not in an ideal position, far from it, I'm trying to find a good antenna to put up on the roof, before I climb up there, I must admit that at the moment both the jpole and the bicone are just winning, but they both have points on the plus and minus side.

      Dave

      Comment


      • OK - DIY 8+1/4 λ CoCo is now fitted into a Fiberglass tube and connected to a 8$ DVB-T stick with FA1090 filter

        DSC_0021.jpg
        before - my CoCo still at PVC tube ....

        DSC_0022.jpg
        after tube change ....

        8035348da8824b91965d293f20292f37.png
        at roof

        02b05c9dd4184caba9078aa3b5f50dbb.jpg
        dump1090 result

        cca30c4061a0468e9ab1f90a02a5ae99.jpg
        adsbscope result
        Best Regards

        Volker

        Comment


        • Originally posted by volkerjacob View Post
          OK - DIY 8+1/4 λ CoCo is now fitted into a Fiberglass tube and connected to a 8$ DVB-T stick with FA1090 filter
          ..................
          GREAT! CONGRATULATIONS

          Comment


          • Originally posted by abcd567 View Post
            GREAT! CONGRATULATIONS
            now i think about a amplifier, but i don`t know, if its worth ......
            Best Regards

            Volker

            Comment


            • yeah that is the trouble with being near a busy airport, all the close by traffic drowns out the distant traffic.
              T-EGLF8

              Comment


              • I am really impressed about the creativity of this thread contributors!

                I am new here and still trying to figure out the best antenna for my setup.
                At the moment I am just using simple DYI "spider" antenna and trying to increase its range.

                I have discovered that adding a splitter (pictured on the right) increased the range about 30%, however when I used Sat-TV splitter (pictured on the left) the range went up another 30% and more than doubled the number of messages received by mutability. Probably this splitter eliminates the interference that comes from <IMG_20161204_135859.jpg950MHz range!
                Having said that It would be really interesting if someone could try it and report here the results...
                ======
                T-EBCI32 (Raspberry PI 3 + RTL2832U/R820T2 USB dongle + Axing SVS 2-01 inline amp + TA1090EC filter)

                Comment


                • Buying from China is a lot more tedious than I expected.
                  Last time I wrote here was around september and the last part of stuff I ordered arrived only last week.

                  My shopping spree included a "simple spectrum analyser", some noise sources, directional couplers, attenuators, antennas, a kilo of connectors, cables, filters and amplifiers.
                  Waiting for them was hard so I started sketching some PCB's for antenna, hairline filters, amplifiers and power injectors. These got also manufactured but this time locally so I had them a month before all parts came from China.

                  This period is extremely busy at work so until I find some time to write more extensively about my tests, here is a picture of the PCB antenna measurements I took earlier today.
                  antenna.png

                  Comment


                  • Last year I purchased the "Noise Source/Simple Spectrum Analyser" (see photo below) from eBay/Chinese seller, and a 12V DC power supply for it.
                    It burnt out within a week.
                    During this one week, it became so hot that I used it to fry eggs.

                    HINT:
                    (1) Use a cooling fan
                    OR
                    (2) Dont use 12V DC supply. Use 9V or 10V DC Supply.
                    s-l500.jpg
                    Last edited by abcd567; 2016-12-08, 17:02.

                    Comment


                    • Last year I purchased the "Noise Source/Simple Spectrum Analyser" (see photo below) from eBay/Chinese seller, and a 12V DC power supply for it.
                      It burnt out within a week.
                      During this one week, it became so hot that I used it to fry eggs.

                      HINT:
                      (1) Use a cooling fan
                      OR
                      (2) Dont use 12V DC supply. Use 9V or 10V DC Supply.
                      s-l500.jpg[/QUOTE]

                      First of all I would like to say Hello to all users.
                      I'm new here but I have some experience with amateur radio. Of course it is nice to have some equipment to simulate/test antennas behavior. But IMO simulation is nice but has nothing to do with practical antenna behavior. At the moment I'm performing some homebrew antennas tests according to abcd567 request, same hardware, same position. I need a couple of days to complete.
                      BTW F-connectors are cheap and easily available worldwide but using SMA AND/OR N-type is little bite more professional.
                      For those who don't believe I suggest to visit Amphenol website and check connector parameters (F, N, SMA, MCX, and so on...)
                      CantennaCollinear24h.jpg[QUOTE=abcd567;86822]
                      This is kind of reference.
                      Last edited by MDA; 2016-12-11, 18:57.

                      Comment


                      • Originally posted by ttalex View Post
                        ............
                        I have discovered that adding a splitter (pictured on the right) increased the range about 30%, however when I used Sat-TV splitter (pictured on the left) the range went up another 30% and more than doubled the number of messages received by mutability. Probably this splitter eliminates the interference that comes from <[ATTACH=CONFIG]8226[/ATTACH]950MHz range!
                        Having said that It would be really interesting if someone could try it and report here the results...
                        It seems you have strong RF noise at your location.

                        If strong RF signals such as on-the-air-TV, FM, Amature Radio, Police, Fire, Taxi etc are present, these are picked by the antenna, reach the DVB-T receiver, cause its overload, and result in reduction in performance.

                        The splitter on right is simply a divider, which divides signals of all frequencies at input to two outputs for use by two receivers. It also introduces a loss (attenuation) of 3 to 6 dB, and this attenuation removes overload of your DVB-T dongle, and improves results.

                        The splitter at left is a frequency band splitter/combiner and is known as diplexer. It divides the incoming signal into two bands of frequencies: TV (5 - 860 MHz) and SAT (950-2400 MHz), and sends each band to its output port. If you connect your DVB-T to the out port marked SAT, it will get only signals between 950 and 2400 MHz, which includes ADS-B 1090 MHz, but dont receive TV and Mobile/Cell Phone signals which are below 950 MHz. This removes considerably the overload of DVB-T and improves performance.

                        The Diplexer (at left in you photo) acts as a Filter.
                        The Splitter (at right in your photo) acts as an Attenuator.
                        Last edited by abcd567; 2016-12-13, 18:18.

                        Comment


                        • Originally posted by abcd567 View Post
                          It seems you have strong RF noise at your location.

                          If strong RF signals such as on-the-air-TV, FM, Amature Radio, Police, Fire, Taxi etc are present, these are picked by the antenna, reach the DVB-T receiver, cause its overload, and result in reduction in performance.

                          The splitter on right is simply a divider, which divides signals of all frequencies at input to two outputs for use by two receivers. It also introduces a loss (attenuation) of 3 to 6 dB, and this attenuation removes overload of your DVB-T dongle, and improves results.

                          The splitter at left is a frequency band splitter/combiner and is known as diplexer. It divides the incoming signal into two bands of frequencies: TV (5 - 860 MHz) and SAT (950-2400 MHz), and sends each band to its output port. If you connect your DVB-T to the out port marked SAT, it will get only signals between 950 and 2400 MHz, which includes ADS-B 1090 MHz, but dont receive TV and Mobile/Cell Phone signals which are below 950 MHz. This removes considerably the overload of DVB-T and improves performance.

                          The Diplexer (at left in you photo) acts as a Filter.
                          The Splitter (at right in your photo) acts as an Attenuator.
                          Thanks a lot for clarification - I have done some more reading about the subj and your comments definitely make sense to me!

                          I need to play some more with my setup as I get huge number of messages at peak traffic (up to 1000/sec) while the distance range is quite low...
                          range.jpg
                          So far I only have special ADS-B filter in between the DVB-T stick and antenna and will try co-linear antenna istead of DIY "spider".

                          Out of my curiosity, how many messages per second can DVB-T stick handle?
                          Last edited by ttalex; 2016-12-22, 02:41.
                          ======
                          T-EBCI32 (Raspberry PI 3 + RTL2832U/R820T2 USB dongle + Axing SVS 2-01 inline amp + TA1090EC filter)

                          Comment


                          • Since the new "Flightaware USB Pro Stick Plus" with integrated filter is now available,
                            does anyone of you already have userexperience compared to the previous combination of extra "Flightaware USB Pro Stick" + extra "Flightaware Filter"?

                            Comment


                            • majo:
                              I have tried both the Orange ProStick and the Blue ProStickPlus. I also have seen reports by other users of ProStick Plus.

                              In most situations, the Blue ProstickPlus with built-in filter performs same as Orange ProSick+Filter combination.

                              However in some locations with lot of RF noise (like mine), the Blue ProStickPlus performs poor and requires an external filter.

                              Please see this thread for details:
                              http://discussions.flightaware.com/a...38099-125.html

                              .

                              Comment


                              • @abcd567:
                                Thank you, that is a good idea to have the second eye on the flightawareforum!

                                I think the "RF noise" you mentioned is a key factor. After 2 years of feeding I pretty much know what to expect from various combinations of rpi, antenna, dvbt-dongles, cablelenght, powersupply, etc. More often surprises are obviously caused by this obscure RF noise.

                                Do you have an idea or simple way to detect and quantify RF noise at a given location?

                                Comment

                                Working...
                                X