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Thread: Suggested designs/products

  1. #11
    Engineer for Jesus Christ IBCrazy's Avatar
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    1. Sadly, there is no way to reduce the antenna size. 2.4GHz is planty small. I just tape a side feed 1.3GHz antenna to my wing. I only ever broke them in handling and have since fixed that problem.

    2. At our video frequencies, nothing is cheap and easy. The circuit you linked to will work only if it is built precisely. I suggest you instead build a wheatstone bridge circuit with a dummy load. Use a microwave diode to find the DC voltage between the dummy and the antenna. You MUST build the circuit so it fits in a space of less than 12mm square and encase it in a metal box or it will resonate!

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  2. #12
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    IB because you have the RF knowhow, it would be really nice if you would/could make a sub 20$ harmonics filter for killing the harmonic frequency of 1280MHz... And the product would sell like hot chocolate in the winter

  3. #13
    Engineer for Jesus Christ IBCrazy's Avatar
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    What about OMM's notch filter? That works well.

    Additionally, Jerrod (Volto) was working with some microchip RF filters for UHF radios. I need to test them once he's got one built. If they work, all it takes is a quick chip replacement to make a 1280MHz filter.

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  4. #14
    A really high gain (>14dBI) 1.3Ghz antenna would be an instant success. Right now, 1.3ghz looks promising for long range but antenna choice is pretty limiting.

    Would it be feasible to build a larger, higher gain patch antenna for 1.28Ghz?

    Thanks IBCrazy, Keegan
    Last edited by PilotKeeg; 19th August 2011 at 05:04 PM.

  5. #15
    Navigator Jameson's Avatar
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    +1 vote for high gain 1.3Ghz antenna, I would also suggest patch tx antenna for UHF systems - it would be perfect for flying in noisy areas, I still think it's better to use (semi)directional antenna instead of 8W booster :-)

  6. #16
    could quit if I wanted to volto's Avatar
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    Check your PM Alex

  7. #17
    Engineer for Jesus Christ IBCrazy's Avatar
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    Quote Originally Posted by PilotKeeg View Post
    A really high gain (>14dBI) 1.3Ghz antenna would be an instant success. Right now, 1.3ghz looks promising for long range but antenna choice is pretty limiting.

    Would it be feasible to build a larger, higher gain patch antenna for 1.28Ghz?

    Thanks IBCrazy, Keegan
    A high gain antenna on 1.3GHz would be a monster, but I can make one. A double BiQuad would be 13dbi, but it would be huge.
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  8. #18
    Engineer for Jesus Christ IBCrazy's Avatar
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    Quote Originally Posted by volto View Post
    Check your PM Alex
    Hey now, R&D is my department

    Good to see you are experimenting. I'll let you know when I'm ready to test.

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  9. #19
    Engineer for Jesus Christ IBCrazy's Avatar
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    Quote Originally Posted by Jameson View Post
    +1 vote for high gain 1.3Ghz antenna, I would also suggest patch tx antenna for UHF systems - it would be perfect for flying in noisy areas, I still think it's better to use (semi)directional antenna instead of 8W booster :-)
    433MHz patch would be huge! I might introduce a MOXON rectangle for UHF. Anything bigger than that would be unwieldy.

    I will look into alternative 1.3GHz antennas. Maybe a quagi?

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  10. #20
    is it true though IBCrazy that if you triple the size of a patch you double the gain? If so than I'll just make some extra large patches

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