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Thread: best antenna

  1. #2581
    Captain abcd567's Avatar
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    Quote Originally Posted by jcinnb View Post
    are you zip tying the radials to outside of cable, or stuffing them down in the insulation. My eyes are not what they used to be?
    All the 4 radials were inserted between the outer PVC jacket and the braid of the coax. The zip ties were used to secure the radials in position, as these have a tendency to move and change 90 degree angle with each other.

    After completion, I checked the continuity between the body of F-connector at other end of coax, and each of 4 radials by a multitester. All 4 were found electrically continuous, as the multitester beeped on each radial.

    The radials were inserted in the same way as a center wires of a Coco are inserted between the PVC jacket and braid of adjacent elements.

    Here is a larger size photo of the monopole with radials inserted and zip-tied.


  2. #2582
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    Got it, thank you.

  3. #2583
    Passenger Ronny Jonckers's Avatar
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    My "Super" coco, the experiment continues...
    from 202nm to 295nm with wideband amplifier and 1090 MHz filter
    Coco + LNA+Filter.jpg
    Coax (75 Ohm 707CRT2) go in the chimney...
    Coco schouw.jpg
    the result:
    Coco special 1...jpg

    total height of 6 meters + 1 meter Antenna (8 x 114 mm)
    20160919_181134.jpg
    Last edited by Ronny Jonckers; 2016-09-21 at 08:02.

  4. #2584
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    I became a little tired of all this blind probing. It takes too much time to fine tune antennas, cables, filters, stubs etc.
    Weather is also not helping as it rains much and I can't open my roof windows to put up test rigs.

    I came upon this article and ordered all that I needed, mainly the noise source, some filters, a metal encased SDR and a directional coupler.
    Waiting starts now but I will jump on some SWR tests the moment all parts arrive.

    Edit: definitely becoming a costly hobby...
    Last edited by ccz; 2016-09-20 at 22:28.

  5. #2585
    Passenger Ronny Jonckers's Avatar
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    My "Super" PCB, now with wideband amplifier and 1090 MHz filter.
    20160907_144217.jpg
    Same configuration as by the coco, but with 50 Ohm H155 coax, top height 6 meter (top chimney) + 50 cm (pvc tube + PCB Antenna)
    LNA+Filter.jpg
    P9210003.jpg
    The result: from 105nm to 321nm
    Super PCB.jpg
    Last edited by Ronny Jonckers; 2016-09-21 at 11:53.

  6. #2586
    Captain abcd567's Avatar
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    Quote Originally Posted by ccz View Post
    I became a little tired of all this blind probing. It takes too much time to fine tune antennas, cables, filters, stubs etc.
    Weather is also not helping as it rains much and I can't open my roof windows to put up test rigs.

    I came upon this article and ordered all that I needed, mainly the noise source, some filters, a metal encased SDR and a directional coupler.
    Waiting starts now but I will jump on some SWR tests the moment all parts arrive.

    Edit: definitely becoming a costly hobby...
    Great!
    Some noise sources heat up too much. I purchased one which became so hot I used to fry eggs on it . Few days after purchase, it burned itself to death
    Someone has installed on his similar noise source, a recycled cooling fan from a discarded video card, and it is still surviving.

  7. #2587
    Captain abcd567's Avatar
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    Quote Originally Posted by Ronny Jonckers View Post
    My "Super" PCB, now with wideband amplifier and 1090 MHz filter.
    .....image snipped.......
    Same configuration as by the coco, but with 50 Ohm H155 coax, top height 6 meter (top chimney) + 50 cm (pvc tube + PCB Antenna)
    .....image snipped.......
    .....image snipped.......
    The result: from 105nm to 321nm
    .....image snipped.......
    Wow, great, congratulations.

  8. #2588
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    Quote Originally Posted by Ronny Jonckers View Post
    The result: from 105nm to 321nm
    Super PCB.jpg
    Nice, good work!
    Would you mind posting also the lower part of the stats? Just pick a full day on this antenna.
    I am interested in the histogram mostly.

    Here is my spider:
    charts.png



    Quote Originally Posted by abcd567 View Post
    Great!
    Some noise sources heat up too much. I purchased one which became so hot I used to fry eggs on it . Few days after purchase, it burned itself to death
    Someone has installed on his similar noise source, a recycled cooling fan from a discarded video card, and it is still surviving.
    Thanks for the advice, will look out of excessive heat.
    I ordered 2 different models, both were around 15$. I could make a mini review of them after trying them out.

  9. #2589
    Passenger Ronny Jonckers's Avatar
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    @ccz
    The lower parts of the stats:
    Plot and Histogram.JPG
    When I move the mouse over the histogram, I see
    46 trackings above 150nm With a maximum of 321nm
    1x160nm
    1x166nm
    1x172nm
    1x173nm
    1x174nm
    1X177nm
    1x178nm
    3x179nm
    1x180nm
    1X184nm
    1x186nm
    5x197nm
    1x200nm
    1x202nm
    3x206nm
    1x212nm
    2x213nm
    2x214nm
    1x220nm
    1x226nm
    1x233nm
    1x241nm
    1x251nm
    1x258nm
    1x260nm
    1x264nm
    1x273nm
    1x275nm
    1x283nm
    1x292nm
    1x301nm
    1x302nm
    1x309nm
    1x312nm
    1x315nm
    1x321nm

  10. #2590
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    @volkerjacob:

    1) You need to compare your 8+1/4 λ CoCo with a reference antenna at same location and heigt to asses how good/bad your CoCo is.

    A 1/4 λ Ground plane antenna is a 'sure and easy to make' antenna, and serves as a good reference/benchmark antenna.

    2) What is GFK? Can you please give it's full name?

    3) Increasing antenna height improves range/plane count/messages.

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