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My first collinear antenna

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  • Originally posted by abcd567 View Post
    @FR24-BB8
    1) How many km or nm is outermost ring (red)
    OR
    how many km or nm between adjuscent rings

    2) Now try with one element removd (i.e. 4 element coco) and then add 2 elements (i.e. 6 element coco), and try again.

    Please note that 2 consecutive full elements balance each other, hence even number of full elements make a balanced coco, and is expected to give better results than one with odd number of full elements.

    ** full element = 1/2 wavelength x Velocity Factor of coax
    They are the same as my earlier posts, the outer most red ring is 200 nm and they are 25 nm between (50 nm between the red lines)

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    • I will prepare my coco for further tests with 4 elements while my spider is online.

      @abcd456
      And i fully understand the "** full element = 1/2 wavelength x Velocity Factor of coax"
      Last edited by FR24-BB8; 2016-07-06, 21:02.

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      • Originally posted by FR24-BB8 View Post
        I will prepare my coco for further tests with 4 elements while my spider is online.

        @abcd456
        And i fully understand the "** full element = 1/2 wavelength x Velocity Factor of coax"
        I know YOU understand it, but my post will be read by so many others in future, and some of them may not know what I mean by full element.

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        • Originally posted by abcd567 View Post
          2) Now try with one element removd (i.e. 4 element coco) and then add 2 elements (i.e. 6 element coco), and try again.
          So is it worth to try with 4 first or should i go for 6 right away? I mean do i get better gain from 6 than from 4?

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          • Originally posted by abcd567 View Post
            I know YOU understand it, but my post will be read by so many others in future, and some of them may not know what I mean by full element.
            Ok, sorry for that.

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            • Originally posted by FR24-BB8 View Post
              So is it worth to try with 4 first or should i go for 6 right away? I mean do i get better gain from 6 than from 4?
              Since you already have 5 elements, you can go either way, 4 first or 6 first, whatever suites you.

              When I make a coco, I start with 4 element & test. If results are promising, I add 2 elements (i.e. make it 6 element) & test. If find 6 better than 4, I add 2 more (i.e. make it 8 element) and test again.

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              • Originally posted by abcd567 View Post
                Since you already have 5 elements, you can go either way, 4 first or 6 first, whatever suites you.

                When I make a coco, I start with 4 element & test. If results are promising, I add 2 elements (i.e. make it 6 element) & test. If find 6 better than 4, I add 2 more (i.e. make it 8 element) and test again.
                So what is your findings from all of your tests? Is it that you can get better result from a coco than from a spider?
                From my point of view i would be much happier if i can get the same result from a coco as from a spider because i think the coco is much more weather proof than the spider.

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                • @abcd567

                  Just to clarify, from my tests so far, iīve got the best results with a spider.

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                  • Same is the case with me. In last 3 years, I have made nearly one dozen Cocos, and all perforformed worst than Cantenna/Spider.

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                    • Yeah, i seem to get coverage round 180 nm, maybe thats all i can get from my position. But iīll try some more to see if i can tweak it a bit more.

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                      • @FR24-BB8
                        Have you checked what is your maximum range limit due to terrain around your location?

                        What is the Maximum Range I can Get?
                        .

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                        • After my repeated failures with coco, I have stopped trying to make any more coco, and use following:
                          System 1: Flightaware antenna+FA Filter+FA ProStick
                          System 2: Cantenna (or Spider made of coax only) + DVB-T dongle (black).

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                          • Originally posted by arya1000
                            can you make a post on how to build it ? i want to try making one too.
                            If you mean the black rod shaped antenna, then I did not built it. I purchased it from amazon.com. It is made & sold by FlightAware:



                            If you mean the Cantenna (the red color can above the rod antenna), then please see this thread:

                            3 EASY ANTTENNAS FOR BEGINNERS The main disadvantages of stock antenna supplied with DVB-T USB Dongle are: (1) It has a very short lead. Due to this, in most cases the antenna cannot be placed at an optimum location. (2) The stock antenna is not optimized for 1090 Mhz. SOLUTION FOR PROBLEM (1): The short cable


                            .

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                            • Originally posted by abcd567 View Post
                              @FR24-BB8
                              Have you checked what is your maximum range limit due to terrain around your location?

                              What is the Maximum Range I can Get?
                              .
                              No i have not. I've been busy with other things the latest days so my antennas had to step aside I'll check this tonight, and I'm thinking of assembling a cantenna to. Interesting to compare all the different variants.

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                              • @abcd567

                                Apparently my location isnīt supported by this site. To bad it would have been nice to see my maximum range.

                                deny.PNG

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