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Improving my coco antenna

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  • #16
    Originally posted by fungus View Post
    Just exercise a little caution when using PVC conduit to enclose your coco. Some, but by no means all, PVC conduit can degrade the signal you're attempting to receive. There is plenty of advice on the net re testing of these conduits but I've found the safest (buggered if I'm sticking it in the microwave oven) is to try it inside the property with and without it for comparison before hoisting it up the mast.

    Some also require painting as they aren't UV protected and that too can be problematic depending on the paint used.

    Sounds like you've got everything else pretty well covered. It is indeed fun isn't it?

    Regards,
    Gregg
    Gregg, I'm a late-comer to this but have built myself an 8 element CoCo out of left-over RG6 (left over from when we'd cancelled our Foxtel) using the dimensions given by abcd in the other thread. I've got it installed in some Holman 15mm PVC-U pipe that I got from Bunnings. As far as I can tell there doesn't seem to be too much signal degradation - I'm getting around 130-140Nm with about 2m sticking out of a J-bracket that I bought from Jaycar. Next step is to add one of those 20db satellite amps that I got off ebay for around $6 and a Kingray power injector that I bought from Jaycar.

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    • #17
      Originally posted by petercr View Post
      ... 8 element CoCo ... 130-140Nm ... 20db satellite amps
      Get any 5dB antenna that is tuned properly and you will get 200+ nm with a decent cable and an FA Prostick.

      Your system is underperforming and adding a SAT amp is not going to solve that unless you have terribly high cable attenuation today.

      /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

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      • #18
        Originally posted by MrMac View Post
        Get any 5dB antenna that is tuned properly and you will get 200+ nm with a decent cable and an FA Prostick.

        Your system is underperforming and adding a SAT amp is not going to solve that unless you have terribly high cable attenuation today.

        /M
        I can vouch for that. The FA antenna opened my eyes yesterday, right after that I was turning down the Pro Stick gain!

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        • #19
          Originally posted by MrMac View Post
          Get any 5dB antenna that is tuned properly and you will get 200+ nm with a decent cable and an FA Prostick.

          Your system is underperforming and adding a SAT amp is not going to solve that unless you have terribly high cable attenuation today.

          /M
          I'm trying the least costly options first - if you notice above the coax cost me nothing and the amp only cost $6 (the power supply was lying around from a previous TV installation). Since ordering that, I've also ordered a FA Prostick+ from a local Australian supplier which I'm hoping won't take too long to arrive. The antenna would be the last option as that'd be another $100 on top.

          All the cabling is RG6 with the run from the antenna connector to the DVB-T stick being quad-shielded and the length being kept as short as possible. There's also local geographic and arboreal conditions that I've had to take into account so I humbly think 140Nm isn't too bad considering.
          Last edited by petercr; 2018-03-21, 20:50.

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          • #20
            @petercr:
            I suggest you determine the maximum range you can get at your location using method described in the following thread. This will serve as a reference for you to judge how good or bad your system is.

            What is the Maximum Range I can Get?

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            • #21
              Hi abcd, that was one of the things I noticed when reading through the other thread and my current range is somewhere in between the blue and orange lines so I know there's some room for improvement... It's a hobby for me so I'm not going to go out and spend lots of money to achieve maximum results when I can get reasonable results... (and I've only really been getting into this over the last few weeks). We have a mobile phone / cellular tower about a km away (line of sites from my house) so that might have some impact too...

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              • #22
                Have you tried Quick Spider. It requires about 1 meter of RG6 coax, two cable-ties, and a twist-on F-connector. It costs hardly a dollar! I got very good results from it. No harm in trying. Instructions to make it are in this thread:

                Quick Spider - No Soldering No Connector

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                • #23
                  That was the second one I tried after the 'Mexican Beans' cantenna (which was a perfect size but too heavy to sit on top of the pipe, kept bending in the wind) ... Was only getting around 60Nm but that was using RG59 coax for the downlead...

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                  • #24
                    Have added the power inserter, amp and DC blocker and managed to get the antenna another 1.5m higher (top is now nearly 7m above ground level). VRS give me the following;
                    ADS-B range.png

                    (range circles are 50km) Range to the SE is blocked due to a very large mango tree two houses away, the west by the D'Aguilar Range which is only about 10k's away

                    and for comparison from HeyWhatsThat
                    HeyWhatsThat Range.png
                    FR24 stats now say I'm getting an increased number of hits between 150 and 200Nm and I'm now seeing some planes over 200Nm.

                    At some stage if I can borrow a ladder to get on the roof, I might see if I can co-locate the antenna with the TV aerial which sits about 1.5m above the top of the roof line.

                    EDIT: added other image
                    Last edited by petercr; 2018-03-24, 07:35.

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                    • #25
                      An increase of 2-3 metres can have a significant benefit if it takes you above local obstacles. I increased progressively from 9 to about 14 metres and in certain directions get returns out to 200+ nm. However, that 14 metres still doesn't take me clear of some very adjacent trees that effectively wipe out any coverage beyond 40nm in a westerly direction.

                      The theoretical coverage versus actual is shown in the attached diagram, yellow is 20,000 and Red 40,000. Actual coverage is shown in black. The diagram is a bit out of date and actual coverage has improved a bit to the North since I increased the height from 12 to 14 metres.

                      actual vs real 200_400.jpg

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                      • #26
                        SKETCH 1 OF 2



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                        SKETCH 2 OF 2

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