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  • abcd567
    replied
    Originally posted by IZ8292SWL View Post
    So this afternoon i ran the test that i found in a Flightaware forum post

    You dont have to go to flightaware to find this how-to. I have posted the how-to in both Flightaware and Flightradar24 forums

    Do I need a Filter? - Find RF Signals In Area



    Originally posted by IZ8292SWL View Post

    and those are the results:
    [ATTACH=CONFIG]11197[/ATTACH]

    This test is coming from another USB stick that currently is in a box on the roof.
    I left it there in order to analyze this situation...

    I'm using the Flightaware PRO stick.
    Alone it can't stop all the QRM coming from the GSM cell towers.

    I suppose i have to buy a filter in order to use my antenna on the roof!!
    What do you think?
    GSM800.jpg

    GSM900.jpg.

    You have cell interference in both GSM800 and GSM900.
    Even if you use flightaware blue stick, the filter in it is after the LNA, so the filter will save the tuner from overload by these signals, but LNA will still get overloaded. You may need another filter between antenna and flightaware blue stick.
    Last edited by abcd567; 2019-10-17, 21:50.

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  • IZ8292SWL
    replied
    Hi @abcd567 and thanks for all your tips.
    Today i tried to move the antenna on the roof.
    I had to set the gain settings to about 28 db because, i suppose, i have a very bad GSM signal interference.
    Result were worse than the setup on my balcony.
    I also tried to listen to some airband frequencies and they were pretty noisy and a lot of QRM.
    On my balcony, i can clearly ear the ATIS but not on top of my building, even with a FM bandstop filter attached....
    So this afternoon i ran the test that i found in a Flightaware forum post and those are the results:
    scan.jpg

    This test is coming from another USB stick that currently is in a box on the roof.
    I left it there in order to analyze this situation...

    I'm using the Flightaware PRO stick.
    Alone it can't stop all the QRM coming from the GSM cell towers.

    I suppose i have to buy a filter in order to use my antenna on the roof!!
    What do you think?
    Cheers!
    Last edited by IZ8292SWL; 2019-10-17, 21:13.

    Leave a comment:


  • abcd567
    replied
    IZ8292SWL:

    Anybody used that grey pvc pipes?
    They look ok to put the cable inside and leave only the spider outside on top.
    It will be OK as the spider itself is outside the pipe, hence the grey pipe's RF attenuation wont affect the performance of Spider.

    Spider by jploch.jpg

    Leave a comment:


  • IZ8292SWL
    replied
    Hi! I updated my antenna with a foam covered spider (the one @abcd567 showed above).
    I also bought a blue Flightaware stick.
    Well, this setup made a huuuuge improvement over the one i used so far (a simple generic stick and a modded whip antenna, the one you have to cut to match the frequency).

    This little antenna was a real suriprise
    150-180 messages per second and almost a doubled range over the old setup.
    I guess the final step is to put the spidy on the roof. Currently is outside on the balcony as the previous one.
    Anybody used that grey pvc pipes?
    They look ok to put the cable inside and leave only the spider outside on top.

    tubo-pvc-filett-barra-da-6mt-pn-16-d1-1-2-.jpg
    Last edited by IZ8292SWL; 2019-10-16, 19:53.

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  • abcd567
    replied
    IZ8292SWL:

    If you mean this one, it works equally good.

    QuickSpider-Ver1.jpg

    https://forum.flightradar24.com/thre...-or-N-Conector

    It was my first version of Quick Spider dated 2015. Later I noticed people are so accustomed to bare copper radials and whip, they took it as a toy, and it was mostly rejected.

    Therefore I released next version in which whip's & radial's insulation was peeled off, and this design was accepted immediately
    Last edited by abcd567; 2019-10-15, 09:05.

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  • IZ8292SWL
    replied
    Originally posted by abcd567 View Post
    RG6 cable comes in two varieties

    (1) Low cost: Copper coated solid steel conductor.

    (2) Better quality: solid copper conductor.

    The copper coated steel one's steel starts corroding after the copper coating has corroded.

    To check if the core wire is copper or copper coated steel, use a magnet


    If core wire is solid copper, a thin layer of copper oxide on the surface won't degrade the antenna as already advised by wiedehopf.
    Further oxidation of copper is also prevented by this surface layer.

    However if core wire is copper clad steel, the steel will continue corroding. In this case it is better to apply spray paint (non-metallic) or apply a thin layer of some sealant over the exposed metal of whip and radials.
    Thank you for this tips.
    Well it looks like a coated solid stell... the magnet attracts it.
    For the moment the antenna is working great and i'm waiting for the flightaware stick.
    I also saw an antenna version with the protective plastic still attached to the copper elements.
    Does it work well as this one?
    Cheers!

    Leave a comment:


  • abcd567
    replied
    RG6 cable comes in two varieties

    (1) Low cost: Copper coated solid steel conductor.

    (2) Better quality: solid copper conductor.

    The copper coated steel one's steel starts corroding after the copper coating has corroded.

    To check if the core wire is copper or copper coated steel, use a magnet


    If core wire is solid copper, a thin layer of copper oxide on the surface won't degrade the antenna as already advised by wiedehopf.
    Further oxidation of copper is also prevented by this surface layer.

    However if core wire is copper clad steel, the steel will continue corroding. In this case it is better to apply spray paint (non-metallic) or apply a thin layer of some sealant over the exposed metal of whip and radials.
    Last edited by abcd567; 2019-10-14, 22:39.

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  • wiedehopf
    replied
    Copper oxide on the surface won't degrade the antenna.

    You might want to experiment with bending the top 0.5 to 1cm over, my spider needed quite a bit shorter of a whip to have optimal reception.

    Leave a comment:


  • IZ8292SWL
    replied
    Originally posted by abcd567 View Post
    Apply spray paint or some sealant over exposed whip & radials to prevent corrossion.
    Uhm ok.
    Another tiny bit of silicone?
    Actually i don't think that tiny bit layer of natural copper oxide will affect that much.
    Is like having a plastic cover over them, even thinner.
    What do you think?

    Leave a comment:


  • abcd567
    replied
    Originally posted by IZ8292SWL View Post
    But i'm a bit worried about that copper radials... will they corrode over time and affect reception?
    Do i have to put something on them?
    Apply spray paint or some sealant over exposed whip & radials to prevent corrossion.

    Leave a comment:


  • IZ8292SWL
    replied
    Originally posted by abcd567 View Post
    You are missing two cable ties on outer jacket to hold the radials in position. Without something to grip radials in position, wind will change their orientation, and these wont be equally distributed over 360 degrees.

    Please see two cable ties (black) in the photo below. These ties are provided specifically to grip the radials so that these dont get dis-oriented by motion or wind.
    [ATTACH=CONFIG]11144[/ATTACH]
    Hi!
    There are two transparent cable ties in that picture but are not visible!
    Also i used some silicone as suggested to cover the radials insertion.
    But i'm a bit worried about that copper radials... will they corrode over time and affect reception?
    Do i have to put something on them?
    Cheers!

    Leave a comment:


  • matysldn
    replied
    You may find this helpful with building any type of antenna.
    There is a lot theory about VHF/UHF antennas:

    http://www.tigereye.net.au/vk4ion/do...F_antennas.pdf

    Edit:
    And there also:
    https://www.qrz.ru/schemes/contribute/arrl/chap18.pdf
    Last edited by matysldn; 2019-10-09, 18:23.

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  • abcd567
    replied
    .
    .

    Directional antenna for ADS-B?

    .

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  • abcd567
    replied

    SOURCE:
    https://www.rtl-sdr.com/tag/corner-reflector/


    Directional Antenna with corner reflector.

    Corner Reflector Antenna for 1090-Mhz.jpg
    Last edited by abcd567; 2019-10-09, 01:38.

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  • AlejandroM
    replied
    thank you for your answer. i will check.

    Leave a comment:

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