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Boost Your Range - And Build it Tonight !

Discussion in 'Phantom 2 Vision + Discussion' started by Tails_Up, Jun 17, 2014.

  1. Tails_Up

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    I saw something similar on YouTube, and this is my version. All it takes is a coffee can.

    Choose a 12oz can made of paper. Most of your store-brand ground coffee comes in a paper can with a foil layer covering the paper. This is what you want. I used a hacksaw to saw off the metal ring at the top, and then sawed off two sections about 3 inches wide. You'll want to cut two pieces, sawing or cutting a cross-section of the can, about the same width, around 3 inches.

    So, now you have two rings. cut through the ring and bend outwards a little. Yrim with scissors to get a clean line, and make one piece about 7 inches long, and the other trim down to 6 inches. Nothing critical here. Round the corners a little to make it look nice. In the middle, you'll want to cut a notch. Take your control box and make the notch in the shorter piece just enough to fit over the 5.8 antenna base. On the other piece, cut a deeper, narrower notch to fit over the Wi-Fi repeater. When you finish It should look like this:


    I then use a piece of black electrical tape, with a slit cut in the center, to hold it lightly to the 5.8 antenna. I just want something to hold it steady. Anything non-metallic will work, you don't want to use a piece of the can material because it will de-tune the antenna somewhat. Tape works well, and is sticky enough to hold it to the antenna.

    On the Wi-Fi repeater, you can just slide the curved piece behind it and over the mount. Make sure your notch is deep enough that it centers top and bottom. Keep the notch narrow enough to hold it snugly.

    What we have now is two reflectors that can be taken off or put on as needed. These are certainly not high-gain devices, but from my experiments tonight they make a noticeable difference in range. The metal foil covering works as well as solid metal at these frequencies.

    I flew with these tonight in an open area I fly often. Normally, at about 2000ft, I begin to get FPV dropouts. (at about 200 feet height) and lose control a little beyond that. But with these simple reflectors, I was able to go to 3200 feet without ANY loss of FPV or control. I could have gone farther, but I ran out of open land and didn't want to push it. Try this, it works and you can make them tonight !

    Here's a video I made that may show it better:

    http://www.youtube.com/watch?v=wG4iGoWYbY4&feature=player_detailpage
     

    Attached Files:

  2. varmint

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    Hmm, aren't the repeater patch antennas already directional? I say that rhetorically becuase it doesn't make any sense to me that a reflector would do jack for those, since there wouldn't be any reflected energy incident to the panels?
     
  3. Tails_Up

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    I started out with the intention to boost the 5.8 controller, and made one for the 2.4 as an afterthought. But it makes a noticeable improvement, because the reflector wraps around the sides. While the panel antennas are directional, they still radiate signal in a cartiod pattern. The wrap-around of the reflector throws more signal to the front. It's still a broad pattern, but it makes quite an improvement over stock. And you can revert back to stock easily.
     
  4. plasmo

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    Nice work Tails_Up, thanks for sharing!
     
  5. PhantomRock

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    Tails_Up, thanks so much for sharing.
     
  6. ToThePoint

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    Location:
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    Even with directional beaming you would have some loss due to radiation to others sides.
    Bear in mind that even a directional electromagnetic field starts out as a omni directional radiation that is guided to a direction with reflectors.
    No antenna design is perfect and will always have some not wanted radiation.
    But the main danger in this idea is what it does to SWR.
    You can't alter any design if you don't know the side effects.
    If you don't know what SWR means, google it.
    Its the thing that can destroy your final stage transistor because your messing with something and don't have a clue what you are doing.
    The idea is great but only proves that no antenna design is perfect.
     
  7. dannytroy

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    Sometimes these homemade designs and better that the fancy expensive stuff. I had a problem receiving a signal from my detached garage, from an IP camera. I tried a few different antennas and wound up using one I made from a Dinty Moore beef stew can. I saw this on YouTube and figured I'd give it a try. It worked great. Too bad we can fit a couple of Dinty Moore cans on the DJI transmitter!
     
  8. PhantomRock

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    I would be curious if someone could do some testing. With a SWR of 3.0, he would have a 50% reduction in power, and that is obviously not what is happening, as his range is increasing.

    With antennas like FPVLR, they do the testing. Who tests with all the Chinese antennas that are being used like,
    http://www.amazon.com/Antenna-Aerial-Re ... el+antenna
    It would be nice if someone with equipment could do some testing and inform the group.
     
  9. ToThePoint

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    Thats my general idea also.
    It works but whats the final result ?
    Nice project idea BTW.
     
  10. wharfbanger

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    Agreed. Or even some testing along the lines of the FPV Booster App (compare before and after mod)..
     
  11. flyNfrank

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    There it is right there. And a known reason why we stay away from this mod. This mod is also known to contribute to Fly Aways. Btw, the best option on the market is FPVLR's antenna's which is advertised as a guaranteed Standing Wave Ratio of 1.1 or less.

    However, hats off to anyone that puts in the time to make our copters better.
     
  12. Tails_Up

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    I certainly agree they are excellent designs and I have the FPVLP stage 2 kit to install. I have another controller, and I'll probably leave it stock, so this was just an attempt to maximize what we have to start with, without opening up the boxes. threw this together based on some principles you see in uhf/microwave antennas, especially for the 5.8 controller antenna. Tonight I flew out past 4000 feet with this, and had rock solid FPV the whole time. Everything standard with no boost app. I was amazed at the difference. I then flew around some in the 3500 foot range and had no signal drops at all. I had line of sight, of course, and hope to have the video up soon. This little project might not produce the higher gain of the excellent custom antennas, but it seems to make a nice improvement in signal level over the stock setup.


    Just a fun project, try it and see !
     
  13. philarvropagan

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    Location:
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    After reading few posts on that idea, I have been digging with the idea of making one but with a parabolic shape.
    Even though improvements are already noticable, I wouldn't feel comfortable with an "as it is" reflector, because of all the mentioned side effets.
    For those of you who read french, there is a clear and simple example for wifi router there: http://frpn.free.fr/0divers/chocapic/
    I'm currently preparing one (shape drawn) for a 96mm diameter, 30mm depth, 19mm focal distance.
    Of course, thanks to Excel, it's very easy to change for better fitting values.
    Phil.
     
  14. plasmo

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    Tails_up-
    Maybe as an experiment (if you or someone else is willing to try) :
    It would be interesting to see what happens if you put on the home made reflectors, and fly the Phantom out to a longer-than-expected stock range (like 4000ft or so) and then try removing (one) of the reflectors to see if you get RTH triggered... And then place the reflector back on to see if you can regain control. Maybe try it again with the other reflector as well. This would be cool if you recorded this as well.
    It would certainly show and prove that these reflectors work by using them on the same flight... Just a thought
     
  15. wharfbanger

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    Went to my favourite spot today. 760m previously. 1060m after adding the coffee tin reflectors (control signal lost at 1060m). FPV good all the way at 640 15fps with the Booster App and coffee tin.
     
  16. brunofcampos

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  17. slothead

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    I used to worry about VSWR issues, but aren't most modern transmitters short-circuit proof (and thus VSWR-damage-proof) these days? I think the bigger question is how has this mod been verified by test.
     
  18. Tails_Up

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    Here's the results I've been able to determine so far.

    all these flights are from the same spot, with a clear veiw across a valley. Average altitude was 225 feet.

    With no enhancements, standard equipment, I begin to get video dropouts at about 2500 feet. I lose connection at around 3000 feet.

    With the home-made reflectors, I have a solid video signal out past 4000 feet. My longest flight was 4500 feet, and at that point I still had video but was getting a few dropped frames. Connection loss didn't happen, but it would have within another 100 feet, I think. I got scared and turned back. I've got a video of this flight posted. Overall, with them I can fly in the area at 3500 - 4000 feet out with few if any dropouts.

    Using the enhanced (level 2) antennas on the same controller, same bird, I was able to get to 4800 feet, where I lost FPV. This was only one flight yesterday, andI I haven't had a chance to repeat it yet. I still had 5.8 control.

    So, using this rough guage, the reflectors give you about 50% more range than the standard antennas.

    A few cavets. First, this is a wi-fi free area. With other wi-fi signals, the level 2 antennas will probably perform better than my reflectors because of the circular polarization. After 3000 feet, the terrain changes to wooded hills, which probably affects signal strength and may create multipath. Finally, a higher altitude might/probably would increase the range for all three.

    My main intent in making these was to help with the 5.8 control signal. Half of your signal bounces off of you - where it does no good. The reflector bounces it back front in the direction you're facing. But the surprise is the gain in FPV range. I think that the flaps on each side of the repeater work to concentrate more signal onto the antennas, much like cupping your hands behind your ears lets you hear better.

    would like to hear if anyone else has tried this, and what your experiences are. You milage may vary.
     
  19. srandall25

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    You could use the booster app to further increase your FPV range beyond the control range and then fly it further to test exactly how far your control range is without losing your FPV first... just a thought.. of course that's easy for me to suggest sitting from my seat without any of the risk...lol
     
  20. flyNfrank

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    Since you use to worry about swr's, I'm curious how you monitored it? If there is a device that will do it, I want one. Guess I should begin the research if some info is available.