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Antenna for ACARS and listening to ATC with DVB-T dongle

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  • Antenna for ACARS and listening to ATC with DVB-T dongle

    Hi,
    I already have an FR24 feeder (F-EGNT4) which I obviously use for feeding to FR24. I recently purchased an RTL2832U+R820T DVB-T dongle. I wanted to use this mainly for picking up ACARS messages. As expected, using SDR#, the acars transmissions that I receive are very faint and no decoding software can decode them (even whilst using a large amount of gain) whilst using the stock antenna.

    I don't know a lot about antennas, which is why I asked here: I am looking for an antenna that could let me pick up these ACARS transmissions so that I can decode them. I don't mind making the antenna or buying one as long as it is reasonably priced. I also don't mind whether the antenna is inside or outside. If I was going to go into the bother of mounting it outside, I would rather that it could pick up ATC transmissions as well (however, if this will decrease the range of ACARS transmissions I can recieve, please let me know). Finally, if I do mount an antenna outside, will it need any spacing from the FR24 antenna that is supplied with the reciever?

    I would like monitor ACARS frequencies: 131.725 and 131.525 (not necessarily at the same time)

    Can anyone suggest an antenna that I could buy or make?

    Thanks
    - WeKnowMC
    Last edited by WeKnowMC; 2016-01-25, 21:23.

  • #2
    Originally posted by WeKnowMC View Post
    Hi,
    I already have an FR24 feeder (F-EGNT4) which I obviously use for feeding to FR24. I recently purchased an RTL2832U+R820T DVB-T dongle. I wanted to use this mainly for picking up ACARS messages. As expected, using SDR#, the acars transmissions that I receive are very faint and no decoding software can decode them (even whilst using a large amount of gain) whilst using the stock antenna.

    I don't know a lot about antennas, which is why I asked here: I am looking for an antenna that could let me pick up these ACARS transmissions so that I can decode them. I don't mind making the antenna or buying one as long as it is reasonably priced. I also don't mind whether the antenna is inside or outside. If I was going to go into the bother of mounting it outside, I would rather that it could pick up ATC transmissions as well (however, if this will decrease the range of ACARS transmissions I can recieve, please let me know). Finally, if I do mount an antenna outside, will it need any spacing from the FR24 antenna that is supplied with the reciever?

    I would like monitor ACARS frequencies: 131.725 and 131.525 (not necessarily at the same time)

    Can anyone suggest an antenna that I could buy or make?

    Thanks
    - WeKnowMC
    Yes. For Airband, in specific those frequencies, you can easily construct a ground plane type, or "spider" type antenna, However, it will be somewhat large for indoor use. Using the same construction detailed everywhere on the ADSB forums, using a SO-239 panel mount connector, make the elements 21.435 inches. That will be centered up on your desired frequencies.

    Spacing from your existing ADS-B antenna should be not very critical. If the center of your ACARS antenna is at least 12" from the ADS-B antenna, you should be good.

    If you look around the web, you might find a Radio Shack Cat. No. 20-176 scanner antenna for cheap. Last one I bought was $12 at the local store. They are still on closeout at some locations. Good antenna construction and will cover that band plus UHF airband just fine.
    Last edited by K5TED; 2016-01-27, 04:37. Reason: additional info

    Comment


    • #3
      Originally posted by K5TED View Post
      Yes. For Airband, in specific those frequencies, you can easily construct a ground plane type, or "spider" type antenna, However, it will be somewhat large for indoor use. Using the same construction detailed everywhere on the ADSB forums, using a SO-239 panel mount connector, make the elements 21.435 inches. That will be centered up on your desired frequencies.

      Spacing from your existing ADS-B antenna should be not very critical. If the center of your ACARS antenna is at least 12" from the ADS-B antenna, you should be good.

      If you look around the web, you might find a Radio Shack Cat. No. 20-176 scanner antenna for cheap. Last one I bought was $12 at the local store. They are still on closeout at some locations. Good antenna construction and will cover that band plus UHF airband just fine.
      I've been doing some research and for now, I've decided that I am going to make an indoor 8-legged spider antenna. Will getting an amplifier help in any way? Could this antenna be mounted outside if needed?

      I have been looking on this thread: /threads/8596-3-EASY-ANTENNAS-FOR-BEGINNERS
      I don't have a soldering iron so I am not too sure if I want to go for the soldered version. Will the one that doesn't use the SO-239 and doesn't require soldering work just as well?

      Sorry for all of the questions

      - WeKnowMC
      Last edited by WeKnowMC; 2016-01-27, 20:46.

      Comment


      • #4
        Originally posted by WeKnowMC View Post
        I've been doing some research and for now, I've decided that I am going to make an indoor 8-legged spider antenna. Will getting an amplifier help in any way? Could this antenna be mounted outside if needed?

        I have been looking on this thread: /threads/8596-3-EASY-ANTENNAS-FOR-BEGINNERS
        I don't have a soldering iron so I am not too sure if I want to go for the soldered version. Will the one that doesn't use the SO-239 and doesn't require soldering work just as well?

        Sorry for all of the questions

        - WeKnowMC
        Not sure which 'no-solder' version you are referring to. With elements at over 21", anything that doesn't have a solid base of some sort for supporting those elements will likely just be a floppy mess and will not perform well.

        If not solder and SO-239, are you game for something made of PVC or is this about keeping the cost to almost nothing?

        Consider going commando....

        For indoor use, one could cobble something together with soda straws, copper wire from a piece of CAT5 cable, and some RG6, and lots of tape.

        A 32OZ plastic soda bottle would make a good frame for some antenna made of thin copper wire.


        Really depends on what level of effort you are willing to put into it. How about making a discone or biconical type antenna out of cardstock paper and thin copper wire? How about the same using thin strips of aluminum duct seal tape?
        Last edited by K5TED; 2016-01-29, 17:57. Reason: fun

        Comment


        • #5
          Originally posted by K5TED View Post
          Not sure which 'no-solder' version you are referring to. With elements at over 21", anything that doesn't have a solid base of some sort for supporting those elements will likely just be a floppy mess and will not perform well.

          If not solder and SO-239, are you game for something made of PVC or is this about keeping the cost to almost nothing?

          Consider going commando....

          For indoor use, one could cobble something together with soda straws, copper wire from a piece of CAT5 cable, and some RG6, and lots of tape.

          A 32OZ plastic soda bottle would make a good frame for some antenna made of thin copper wire.


          Really depends on what level of effort you are willing to put into it. How about making a discone or biconical type antenna out of cardstock paper and thin copper wire? How about the same using thin strips of aluminum duct seal tape?
          Hi, first of all, I have decided that I will get the SO-239 and solder the discone/spider antenna together (meaning that I will have to get a soldering iron). I was looking at this design: www(dot)atouk(dot)com/wordpress/?wpdmpro=your-first-adsb-antenna&wpdmdl=397 (sorry, I cant post links until I have over 4 posts)
          Obviously, I would need to make the elements 21.435".

          I would like to try to get the best performance for ACARS as I can with this antenna within a reasonable price (I wouldn't really want to spend more than 30 on it). Now that I think of it, I'm probably going to keep the antenna inside until I've tested it. The only thing now is that I need to find out what kind of wire I could use to try to get best performance. Do you have any suggestions. Also, as I said, would some kind of amplifier help with performance?

          Thanks
          - WeKnowMC

          Comment


          • #6
            Originally posted by WeKnowMC View Post
            Hi, first of all, I have decided that I will get the SO-239 and solder the discone/spider antenna together (meaning that I will have to get a soldering iron). I was looking at this design: www(dot)atouk(dot)com/wordpress/?wpdmpro=your-first-adsb-antenna&wpdmdl=397 (sorry, I cant post links until I have over 4 posts)
            Obviously, I would need to make the elements 21.435".

            I would like to try to get the best performance for ACARS as I can with this antenna within a reasonable price (I wouldn't really want to spend more than 30 on it). Now that I think of it, I'm probably going to keep the antenna inside until I've tested it. The only thing now is that I need to find out what kind of wire I could use to try to get best performance. Do you have any suggestions. Also, as I said, would some kind of amplifier help with performance?

            Thanks
            - WeKnowMC
            I would recommend using the welding rod approach. It's sturdy enough for this size element, and can be soldered with a gun. If you are going to go with buying a soldering iron, keep in mind that for anything over 12g wire, a typical small pencil iron will only create madness. Get a 150w or better soldering gun for these sort of projects and keep the pencil for electronics work. The gun gets things hot quick, which is what you need, dab on the solder and let it go. Make sure you use solder with flux core or buy a tin of flux or a flux pen.

            You shouldn't have to spend more than about 8 for this antenna.

            As for the amplifier, you certainly could benefit from one, but the key to VHF is height. A decent amp is probably going to set you back a little more than 15. Don't try to use a typical home cable tv distribution amp.

            Might as well build the antenna, and see how it performs, then consider what improvements are needed.

            Comment


            • #7
              I have decided on parts for the antenna. See my next post...

              Comment


              • #8
                Originally posted by K5TED View Post
                I would recommend using the welding rod approach. It's sturdy enough for this size element, and can be soldered with a gun. If you are going to go with buying a soldering iron, keep in mind that for anything over 12g wire, a typical small pencil iron will only create madness. Get a 150w or better soldering gun for these sort of projects and keep the pencil for electronics work. The gun gets things hot quick, which is what you need, dab on the solder and let it go. Make sure you use solder with flux core or buy a tin of flux or a flux pen.

                You shouldn't have to spend more than about 8 for this antenna.

                As for the amplifier, you certainly could benefit from one, but the key to VHF is height. A decent amp is probably going to set you back a little more than 15. Don't try to use a typical home cable tv distribution amp.

                Might as well build the antenna, and see how it performs, then consider what improvements are needed.
                I have been looking at parts for the antenna. Before I buy them I would like to make sure that everything will work together.

                Firstly, to connect the DVB-T dongle to the coax cable, I am looking at this: http://www.ebay.co.uk/itm/F-Jack-Fem...hQAAOSwo6lWMIx
                Secondly, for the RG6 coax cable: http://www.ebay.co.uk/itm/10m-Satell...MAAOSw-7RVCZ~d
                Next, I will have the amp connected: http://www.ebay.co.uk/itm/SATELLITE-...gAAOxyTjNSdhHQ
                Then I will plug have this amp connected to this connector: http://www.ebay.co.uk/itm/SMA-female...MAAOSw~gRVqS6d
                After that, it will be connected to the SO-239: http://www.ebay.co.uk/itm/UHF-SO-239...25.m3641.l6368
                Finally, the wire for the elements will be this copper wire: http://www.ebay.co.uk/itm/1mm-ENAMEL...IAAOSwjVVVweD~

                Will these parts all work together without any problems? I would just like to confirm before I buy the parts.

                Thanks
                - WeKnowMC
                Last edited by WeKnowMC; 2016-01-31, 00:21.

                Comment


                • #9
                  Originally posted by WeKnowMC View Post
                  I have been looking at parts for the antenna. Before I buy them I would like to make sure that everything will work together.

                  Firstly, to connect the DVB-T dongle to the coax cable, I am looking at this: http://www.ebay.co.uk/itm/F-Jack-Fem...hQAAOSwo6lWMIx
                  Secondly, for the RG6 coax cable: http://www.ebay.co.uk/itm/10m-Satell...MAAOSw-7RVCZ~d
                  Next, I will have the amp connected: http://www.ebay.co.uk/itm/SATELLITE-...gAAOxyTjNSdhHQ
                  Then I will plug have this amp connected to this connector: http://www.ebay.co.uk/itm/SMA-female...MAAOSw~gRVqS6d
                  After that, it will be connected to the SO-239: http://www.ebay.co.uk/itm/UHF-SO-239...25.m3641.l6368
                  Finally, the wire for the elements will be this copper wire: http://www.ebay.co.uk/itm/1mm-ENAMEL...IAAOSwjVVVweD~

                  Will these parts all work together without any problems? I would just like to confirm before I buy the parts.

                  Thanks
                  - WeKnowMC

                  Suggestions:


                  1. larger diameter wire. For 21" elements, the 1mm stuff will be very floppy. The center pin will take probably up to around a 2.5mm wire, depending on manufacturer. Find the spec sheet and drawing for that specific SO-239 to find out.

                  2. You need something to power the amplifier, i.e., a power injector. These types of inline amps are designed to be powered from a satellite box. Operating voltage: 5 - 18 V max. 30 V DC / 40 mA.

                  I don't use these, but there are several members here who can point you in the right direction on that point.

                  Comment


                  • #10
                    Originally posted by K5TED View Post
                    Suggestions:


                    1. larger diameter wire. For 21" elements, the 1mm stuff will be very floppy. The center pin will take probably up to around a 2.5mm wire, depending on manufacturer. Find the spec sheet and drawing for that specific SO-239 to find out.

                    2. You need something to power the amplifier, i.e., a power injector. These types of inline amps are designed to be powered from a satellite box. Operating voltage: 5 - 18 V max. 30 V DC / 40 mA.

                    I don't use these, but there are several members here who can point you in the right direction on that point.
                    Hi, will this 2mm copper wire do?http://ebay.co.uk/itm/2mm-ENAMELLED-...-/111734897320

                    I have decided that I will leave out the amplifier for now.
                    Other than that, I assume everything is good.

                    Comment


                    • #11
                      Antenna in-line amp

                      Originally posted by K5TED View Post
                      Suggestions:

                      ...amplifier...point you in the right direction on that point.
                      I doubt, the amp wil give you any true advantage, except 18dB gain under discussion if you will succeed feeding this device. The product description points out severe contradictions: "SATELLITE DVB-T Dur-line INLINE amplifier" / "Not suitable for cable TV" / "Frequency range: 5 to 2400 MHz". Aha! If it was not suitable for cable TV, it hardly would amplify 130MHz ACARS. With a frequency range of 5 - 2400 MHz it was suitable for all consumer frequencies up to W-LAN including FM radio, marine, and aviation VHF. To be honest: Try without amplifier. As K5TED said "the key to VHF is height", antenna height. If you manufacture a proper VHF antenna there is a big chance, you won't need an amplifier, because the antenna will give you 10 dB or even more gain compared to the little stock antenna stick.

                      Comment


                      • #12
                        This all got me to cogitating.. :-)

                        This is something I've been wanting to try for while...

                        On a recent hobby store excursion I saw some brass tubing stock, all different diameters. It's not particularly expensive. I believe, using a high quality SO-239 connector, that it would be possible to build a nice groundplane antenna from this.

                        Ground radials could be soldered on in 'pinwheel fashion', and the vertical radiator would be a size that can be solder tinned on the inside, then tin the SO-239, slip the radiator over, then reheat and 'sweat' together. Let cool. Enjoy.

                        This wouldn't likely be a performance improvement over the tried and true brazing rod approach, but simply an exercise in, "will it work?"

                        An even fancier approach might be to use a SO-239 bulkhead type connector, and a brass fender washer drilled out to the connector size, then solder the ground radials to the fender washer. 4, 8 10, whatever. Once that is all put together, use a small, say, 1/2" PCV cap with a element sized hole in the middle, slide over the vertical element to cover the center pin solder point, maybe glue it on there with some RTV, polish the whole thing off then spraypaint with suitable outdoor Krylon. The pole mount could then be integrated with the fender washer easily enough.

                        It'd be easy to build a jig for the element placement and bulk soldering, and also to give the final 'bend' to the elements. For mass production.


                        Brass antennas are common in military and commercial applications, and most of the PL-259/SO-239 connectors we buy today are made of brass with a nickel or silver plating.
                        Last edited by K5TED; 2016-01-31, 17:14.

                        Comment


                        • #13
                          If we just forget about the cost for a minute, what would be the best antenna for ACARS? Also, I'm still debating whether to actually build an antenna or buy a pre-built one. Are there any decent pre-built antennas for ACARS out there?

                          Comment


                          • #14
                            Originally posted by WeKnowMC View Post
                            If we just forget about the cost for a minute, what would be the best antenna for ACARS? Also, I'm still debating whether to actually build an antenna or buy a pre-built one. Are there any decent pre-built antennas for ACARS out there?
                            Sure: http://www.antennaexperts.in/product-detail.asp?id=18

                            Comment


                            • #15
                              .
                              A 2m band (144 to 148 Mhz) J-Pole + 1090 Mhz Franklin

                              Originally posted by lutorm View Post
                              I finally got my antenna up on the roof:


                              I'm now getting 500+ km tracks out over the ocean and wider coverage compared to having it in the window.

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