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Trial Run Results for Three Types of Whip Antennas

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  • scott1304
    replied
    It's a normal dvbt+ dongle

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  • abcd567
    replied
    Originally posted by AlejandroM View Post
    Hello, sorry i mean what kind of adapter you have to trace planes.

    flightradar blue, yellow, or a normal dvb-t dongle.
    This is NOT called adaptor. It is called RECEIVER.

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  • AlejandroM
    replied
    Hello, sorry i mean what kind of adapter you have to trace planes.

    flightradar blue, yellow, or a normal dvb-t dongle.

    Leave a comment:


  • scott1304
    replied
    Originally posted by AlejandroM View Post
    which adapter do you have? for me cantenna is the best option even trying another antennas.
    I've got a mcx to F-Type adapter, cut a small amount from my whip and the range went from 59 down to 40nm, putting a normal sized whip back on increased it to 60nm. want to try and get the best range I can.

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  • abcd567
    replied




    3 EASY ANTENNAS FOR BEGINNERS




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  • AlejandroM
    replied
    which adapter do you have? for me cantenna is the best option even trying another antennas.

    Leave a comment:


  • scott1304
    replied
    I tried the cantenna but signal dropped after 10 minutes or so. Can only pick up 59nm using standard antenna, this is such an interesting topic so will be giving it a try later today and see what the effects are.

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  • AlejandroM
    replied
    wow, this is a really interesting topic.

    i will keep working with the cantenna, i had the whiped antenna but is not working as desired, maybe because it doesnt have a filter on that location ( possibly)

    i found a coffee can, but is 6 inches diameter, can work as cantenna? i will install a new raspberry just to test antennas.

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  • wiedehopf
    replied
    It won't have good performance.

    You can look up antenna impedance but it's a very complicated topic.
    Let's just say, monopole antennas with groundplane are gonna be best at 1/4 wavelength.

    Or you can build a dipole antenna (the half-wave dipole antenna is most common): https://en.wikipedia.org/wiki/Dipole...lf-wave_dipole

    Note that using other than half-wave dipole antennas means you need impedance matching.

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  • AlejandroM
    replied
    i have a question on this.

    If 1/2 wavelenght for 1090 MHz is 138 mm and I want my antenna to be 1/4 weavelenght (=69 mm)

    what happen if an antenna is working at 1/2 wavelenght? it will work?

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  • majo
    replied
    @abcd567:
    Thank you for this quick and competent reply!
    Now I`m confident and can start cutting...

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  • abcd567
    replied
    @majo:
    In antennas, there is a phenomenon called "end effect". Due to this effect the physical length of antenna is slightly shorter than its electrical length by about 97% to 98%. This is mainly due to radio waves travelling slower in metallic wire than in the air, and also due to capacitance effect at the ends of the antenna.

    Taking an average figure of 97.5%, the physical length of full wave wire is 275x0.975=268mm, and 1/4 wavelength wire is physically 1/4x268=67mm
    Last edited by abcd567; 2016-07-11, 21:00.

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  • majo
    replied
    Thank you for this great and easy to realize idea!

    But before I cut my antenna allow one question:
    If 1/2 wavelenght for 1090 MHz is 138 mm and I want my antenna to be 1/4 weavelenght (=69 mm) why should I make the cut at 67 mm (15 mm base + 52 mm whip)?

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  • CX6BX
    replied
    Great info abcd567, i will try this with my old antenna

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  • abcd567
    replied
    @Ben311

    Hello Ben
    There is another step to further improve: Enlarge the tiny ground plane provided by the 1 inch (25mm) dia mag mount base by placing it over a metallic surface like a metallic sheet, plate or a can.

    Please see the following thread which demonstrates the boost when antanna was placed over a metallic surface (a food can), compared to when it was placed over a non metallic surface (inverted glass).

    Trial Run Results for Four Sizes of Ground Planes

    .

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