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  • Originally posted by abcd567 View Post
    @charan:
    You need to add filter at input of amplifier to reject FM and other TV and communication VHF bands. A band-pass filter for air band will reject frequencies higher & lower than air band and pass only air band to amplifier.
    Or a cheaper option would to be add "notch filters" to the offending frequencies, these can be made from simple open ended coax cables...

    http://www.changpuak.ch/electronics/...r_Designer.php

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    • Does anyone know of any antennas similar to the ones posted in this thread under
      "External Antenna (1' / 300mm antenna, total size 2' / 600mm with mounting bracket and antenna cable)" - Mount not required as I plan to mount outside my window however I just don't want an antenna that's ridiculously big or needs mounting on the roof for example. Anything better than this indoor standard DVB-T stick antenna that came with the USB stick - Can achieve 55nm with this, to 100nm. A thin would be preferred to reach further than 55NM.
      Ran on a raspberry PI, prefer not to have anything with external power.

      Thanks,
      Last edited by MatthewE; 2015-01-29, 20:51.

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      • https://www.youtube.com/watch?v=TkUYdCPFXXs

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        • Looked at this thanks although I don't trust myself to make as such as I know it'll go wrong, I unfortunately don't have the time to do so =[

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          • I like this one a bit better.....

            www.ADS-B.ca

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            • Part 2
              www.ADS-B.ca

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              • Originally posted by 1090 MHz View Post
                Part 2
                Just funnily enough watched both, I might try it but I really find working the length, such going to be a pain and as I said I can't mount it on my roof or get a fibre glass pole to extend it! So I didn't really want to go OTT although I'd have liked something somewhat decent if possible.

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                • Originally posted by MatthewE View Post
                  ........I just don't want an antenna that's ridiculously big or needs mounting on the roof for example.
                  Anything better than this indoor standard DVB-T stick antenna that came with the USB stick - Can achieve 55nm with this, to 100nm. A thin would be preferred to reach further than 55NM.
                  Ran on a raspberry PI, prefer not to have anything with external power.

                  Thanks,
                  Try this one (the Cantenna):

                  Cantenna test setup.jpg . DSC03173-R.jpg .DSC03174-R.jpg . DSC03175-R.jpg . DSC03176-R.jpg
                  Last edited by abcd567; 2015-01-30, 01:18.

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                  • @MatthewE:
                    Further details & eaxamples of Cantenna:

                    [ATTACH=CONFIG]5579[/ATTACH] . Whip measurements-R.PNG.png

                    Each one by a different person
                    Cantenna - Beans can.jpg . C&D cantenna.jpg . Cantenna.JPG.jpg
                    Last edited by abcd567; 2015-01-30, 01:55.

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                    • @MatthewE:
                      Each one by a different person

                      tuna fish can monopole_9ame3ehe.jpg . Monopole.jpg . DSC-xxxx2-R.jpg . IMG_20141006_175259 (Small).jpg . DSC03302-R2.JPG.jpeg
                      Last edited by abcd567; 2015-01-30, 01:36.

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                      • Originally posted by abcd567 View Post
                        @MatthewE:
                        Further details & eaxamples of Cantenna:

                        [ATTACH=CONFIG]5579[/ATTACH] . [ATTACH=CONFIG]5589[/ATTACH]

                        Each one by a different person
                        [ATTACH=CONFIG]5581[/ATTACH] . [ATTACH=CONFIG]5582[/ATTACH] . [ATTACH=CONFIG]5583[/ATTACH]
                        Hi, again, abcd567!

                        Am getting excited with these photos of working (cantenna) models... Am still trying to make my first successful coco... There is still something I am not doing well. Indeed, the "dark arts of coco making" are not easy to master. I have gotten tired with making coco antennas for now. I will rest awhile from it by trying these cantennas...

                        Is it possible to point out the exact Post no of a successful build of any antenna? For the cantenna you have posted the construction details again above. How about the exact construction details of a successful coco? I know they are somewhere in the "best antenna" thread but wading thru over 2000posts is not easy. I have been jumping around just looking for coco construction details. I may have read about failed attempts (and not realize it).

                        Recently the construction details of successful Franklin antennas have come up. I have noted these down and will try that later.

                        How about the other antenna builds, like simple dipole, quarter wave antenna, 8-element yagi and 2-stack yagi, wire collinear antenna? If we could have a summary post of ALL antennas built/discussed in the thread. Just the Post no. of the construction details of the successful build... Or perhaps it has been posted already.... Buried in the 2000+ posts of the thread...

                        I have the following; perhaps it can be appended...
                        Cantenna - Post #2196
                        Franklin antenna - Post # 2084 and thereabouts
                        Spider antenna - Post #2142

                        Thanks!
                        Gerry

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                        • @gquejada:
                          You are right. We need to make an index or summary. This thread is 2000 + posts and it is difficult to dig out things.

                          TYPE 1
                          Physically small & simple antennas like 1/2 wave Dipole, Spider, Cantenna etc have advantage of having 75 ohm impedance hence perfect impedance match/SWR without any need for phasing & impedance matching. These are not sensitive to accuracy, and a few mm error will not substantially degrade performance, hence these are good fo DIY novice. However these have disadvantage of low gain (of the order of 1.5 to 2 dBi), hence need an amplifier to cover for weak signals from distant plane and to cover for attenuation in coax feed line.

                          TYPE 2
                          Physically larger, multi element antennas like CoCo, Franklin, Coiled Whips etc have high gain (of the order of 4 to 9 dBi), so give better results compared to tiny ones listed above when both are used without amplifier. However they have biggest disadvantage that these are required to be very accurately made to get proper phasing & impedance match. A few mm inaccuracy completely knocks down these antennas from excellent to poor. The accuracy condition is met in factory environments with computer-aided design, templates, jigs, molds, and test equipment, but is very difficult to meet in DIY situation. Hence the failures.

                          For a new DIY enthusiast, it is best to start with simple tiny ones (type 1) with amplifier added. At later stage the DIY enthusiast can try the more sophesticated ones (type 2)
                          Last edited by abcd567; 2015-01-31, 03:45.

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                          • Originally posted by MatthewE View Post
                            Looked at this thanks although I don't trust myself to make as such as I know it'll go wrong, I unfortunately don't have the time to do so =[
                            For a ready made antenna, search ebay for adsb antenna. They work really well especially the ones from Eastern Europe.
                            T-EGUB1

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                            • Originally posted by abcd567 View Post
                              Try this one (the Cantenna):

                              [ATTACH=CONFIG]5574[/ATTACH] . [ATTACH=CONFIG]5575[/ATTACH] .[ATTACH=CONFIG]5576[/ATTACH] . [ATTACH=CONFIG]5577[/ATTACH] . [ATTACH=CONFIG]5578[/ATTACH]
                              Problem being they're not very sturdy outside
                              In addition you may know the answer, on piAware if I plug the dvbt stick directly into usb it's fine but if I plug it in the same slot using a usb extender it says no devices and won't boot properly?
                              Originally posted by trigger View Post
                              For a ready made antenna, search ebay for adsb antenna. They work really well especially the ones from Eastern Europe.
                              I was looking before, these don't require external power do they? - how long estimate do they deliver within? 7 days?

                              Comment


                              • Originally posted by MatthewE View Post
                                Problem being they're not very sturdy outside
                                In addition you may know the answer, on piAware if I plug the dvbt stick directly into usb it's fine but if I plug it in the same slot using a usb extender it says no devices and won't boot properly?........
                                Example of an 8 legged Spider and a Cantenna mounted outdoors
                                Antennas.jpg

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