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Thread: My config and ways to improve it.

  1. #1
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    My config and ways to improve it.

    Hi this is my 1st post, my native language is not english , so expect a few errors...

    My setup:

    1 x RPI (Raspbian distro on it)
    1 x DVBT pen (from jetvision (expensive by the way same on chine costs 6 euros with postage))
    1 x home made antena (used this how too : youtube.com/watch?v=TkUYdCPFXXs )
    1 x 6 meters RG58 cable
    1 x pigtail from SMA to MCX about 10 cm R316 i think..

    My normal range according to FR24 is 180nm

    This is my virtual radar plot:

    range.PNG


    i know that the RG58 is a bad cable. my calculation says that i am loosing about 3.8 db's.
    How can this affect my range ?
    Do you guys suggest a better cable ?
    My plan is to put my PI and DVB-T stick on a box and use only about 10cm or less of cable that way loosing the less possible.

    about the antenna is there any model better than this one ?


    tanks in advance

  2. #2
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    180 isn't too bad. RG216 or LMR400 is better suited to higher frequency. Means weaker signals will be ignored (IE further out) as will not reach the stick properly.
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers

  3. #3
    Captain abcd567's Avatar
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    Try DIY Antennas "Spider" or "Cantenna". Your coax is not long, only 6 meters, low cost TV dish cable RG6 will be ok. Most of DIY antennas on youtube and internet are easy to make, but hard to get right. The Spider and Cantenna are easy to get right and may give better performance than youtube antennas.

    3 EASY ANTENNAS FOR BEGINNERS

    .

  4. #4
    Captain abcd567's Avatar
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    I have made several CoCo (coaxial collinear), but none give good result. With the best one, I could get 100nm to 150nm. Then I made Cantenna, and I am getting 200 nm to 250nm+.

    See my Cantenna's coverage map plotted by VRS.
    On top-left of the map is my system details (Cantenna+5meters RG6 coax + pigtail + dvb-t usb dongle plugged into computer).



    .
    Last edited by abcd567; 2015-12-02 at 01:51.

  5. #5
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    The can itself becomes a radiator? thats bonkers 0.o
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers

  6. #6
    Captain abcd567's Avatar
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    Quote Originally Posted by Oblivian View Post
    The can itself becomes a radiator? thats bonkers 0.o
    The can is 3-in-1.
    (1) Horizontal circular bottom of can acts as ground-plane.
    (2) Vertical cylindrical wall of can acts as down limb of a dipole, whip serving as up limb of dipole
    (3) Can as a whole acts as a decoupling sleeve.

    Cantenna is actually a wide-bodied derivative of a long-timer "coaxial antenna", also known as "sleeved dipole". This had a 1/4 wave upper limb, and a 1/4 copper tube over coax as down limb. This design was not popular due to not very good perfarmance. I realized that the main cause of these issues is the narrow gap beween coax and the copper tube, and decided to use a much wider dia sleeve. A pepsi can readily fit these requirement, plus easy to cul thin aluminum walls made me select it. This was birth of Cantenna, though its name at bith was 1/4 wavelength sleeved dipole. After couple of months I renamed it "Cantenna". I remember all these events are recorded through my posts in thread "best antenna" some where beteen pages 120 & 150 (June 2014 to Aug 2014). Below is the diagram of non-popular "coaxial antenna"



    Last edited by abcd567; 2015-12-02 at 03:33.

  7. #7
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    Must have a looksee, might be a good alternate for my Rpi which runs the standard antenna that Miro sent with his MicoUSB Dongles.

    I always think of cantenna as the wifi one based on tin-cans. Use to use a pringles can as a directional yagi, Much like wok-fi using a mesh wok
    Posts not to be taken as official support representation - Just a helpful uploader who tinkers

  8. #8
    Captain abcd567's Avatar
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    Quote Originally Posted by Oblivian View Post
    Must have a looksee, might be a good alternate for my Rpi which runs the standard antenna that Miro sent with his MicoUSB Dongles.
    Please see this new thread which I just now created:
    Optimize the Whip Antenna Which Is Supplied With DVB-T Dongle

    I always think of cantenna as the wifi one based on tin-cans. Use to use a pringles can as a directional yagi, Much like wok-fi using a mesh wok
    Yes, both use the name Cantenna because both use can, but function of the Can in each one is completely different. In wi-fi, can is use as a reflector or wave guide, while in adsb cantenna, the can is one limb of dipole (radiator)/groundplane/decoupling sleeve.
    Last edited by abcd567; 2015-12-02 at 04:50.

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