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Signal strength on phantom and gps signal

Discussion in 'General Discussion' started by simonthk, Oct 9, 2013.

  1. simonthk

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    Hello pilots

    So I have used an FPV 200mw for some time, and it works fine. The range is about 500 meter which I will increase with new anteannas.

    But how long is the range on the phantom? And what about obstacles? The antennas that goes for the FPV and phantom hardware seems to be the same. So why should my phantom reach longer than 500 meters with almost the same frequenzy?

    I just want to be sure to not suddenly have it crash or not being able to control it for something like 1000 meter. Can I change antenna or something? And to which kind?

    Also I seem to have quite some trouble catching gps signal now and then, and have to wait like 5 min. Sometimes I just start and fly up, to then catch the GPS signals easier. Anyone know about improving this?

    Thanks
     
  2. DeweyAXD

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    Stock TX will get it to about 700m max with clean line of site in the right conditions (humidity in the air can affect it for example). When you get beyond that point it will activate return to home mode.

    You say 'almost the same frequency'... this is confusing. Your FPV will likely be on 5.8ghz? If you are using 2.4ghz for FPV you are risking conflict with the 2.4ghz flight TX/RX.

    Yes you 'can' change your antenna but it will be a DIY solder job and I really wouldn't advise it. The TX isn't the problem, the RX in the Phantom is. It is a tiny chip, not shieled very well and hence not a lot of balls to it. If you want 1000m you will need to buy a full range TX/RX setup like a Futaba or Spektrum. You simply won't get 1000m with the stock setup.

    This is highly unwise to do especially if you are pushing the range of the TX.... if you don't have full GPS on takeoff it won't lock your home point (10+ green flashes iirc). Sure you will be using GPS to stabilise when you get in the air but if you lose signal it will have nooooo idea where home was and you are very very likely to wave goodbye to the whole kit.

    If it takes 5 mins you need to change location. If you are in or around trees or buildings they can block signal to all satelites. People forget that Satelites are not just straight above you.... there are plenty on the horizon line and low in the sky so obstructions will get in the way. Where do you fly?
     
  3. Dns_Rui

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    Waiting like 5 minutes isn't normal. I wouldn't fly again without at least connect the phantom to the pc and open naza assistant, check if there's any warnings, check calibrations, redo them as needed. Then, if there are still issues, i would open the phantom and check all cables connections.
    Range of the phantom:
    viewtopic.php?f=4&t=3107&start=10
    viewtopic.php?f=6&t=2900&p=21258#p19572
     
  4. simonthk

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    Thank you

    Have anyone run into anyone who made changes to the stock parts for better range? I just cant seem to figure out why buy new stuff, if I can upgrade something I already have :) also am short on money. I can do any electrical fixes needed.
     
  5. miskatonic

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    On a cold boot waiting 5 minutes to get at least 6 GPS signals can be normal. It depends on the time of day and your location. I live in San Francisco, It takes me about 5 minutes to get GPS lock at noon from a cold boot. If I go out a few hours later it takes less than a minute or two.
     
  6. miskatonic

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    Better range does not mean better flying time. You will need to add extra batteries if you want to fly farther. Also if you are going to be running FPV in the US you are required to have a amateur radio license. Good luck getting one of those at the moment. The FCC is closed. ;)
     
  7. simonthk

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    I am from Denmark and am gonna fly over private ground, which is legal. The ground is 800 meters with quite some obstacles. I wanted to do a "quickfix" to just improve my signals abit and with low cost.
    In Denmark you also need a licens when flying over not private ground. It cost 1880 $ to get, 100 papers, rules and flying notes and you need ensurance for 450 $ a year :) welcome to Denmark, here we may not have fun. Aaaand the license has to be renewed each second year.
     
  8. simonthk

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    My idea is, that if these antenna´s can improve the range of my FPV, why cant there be an improvement on the phantom? http://www.ebay.com/itm/5-8g-3-Blade-Cl ... 1c34ec0fc1

    The phantom has like no antenna :) anywho, maybe I should be the first one to try this stuff out.
     
  9. BruceTS

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    By the time you invest in the equipment and time to upgrade your stock Tx/Rx you could have purchased a new one. You can't just slap on an antenna without tuning, otherwise you can make things worse.

    The threads that I've read about others that have optimized theirs have gotten good range, but they or friends of theirs had the proper equipment and experience to make the modifications.
     
  10. simonthk

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    Thank you
    Do you have any links referred to what you are saying? I just cant find anyone on the whole internet, it is empty for me :)
    Im not afraid of getting new experience, and I surely have the equipment and knowledge on electronics.
     
  11. martcerv

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    The antenna is not the issue with the stock TX and using a 5.8g polarized antenna simply wont work on 2.4g radio very well if at all. The antenna needs to be properly tuned to the frequency and be matched with the RX, having a linear polarized antenna basic straight antenna in the rx and polarized in the TX wont work. You could always try some 2.4g antennas for a test but the main issue is the low power of the stock TX and very small and weak RX.

    If you see the size of the antenna on the Futataba 8FGS I use its even smaller then the stock phantom TX yet I have flown it to 2km along with the DJI AVL58 setup and DJI cloverleaf antennas. The Futaba antenna is smaller yet has more then double the range as I took the stock controller to between 700m-1km where it would lose signal. The Futaba with LOS is still fine at 2km and Im sure it can go a bit further but I have little need to go beyond that range.

    I dont know if anyone has really tried circular polarized antennas on the radio and even on the very long range UHF systems they still use a straight linear antenna so there must be some reason. The Futaba receiver same as the new DJI one uses 2 antennas meant to be positioned at 90 degrees to eachother so its a diversity antenna working better when the quad is pitched at most angles. Putting any larger antenna isnt the solution it needs to be correct for the wavelength and the tx rx is very critical in overall signal strength not only the antenna. Putting the wrong antenna will make things worse so I dont think there is any reason to mess with the antenna and the crappy stock rx is the main issue. Also the tx can be run for months without need for new batteries and my futaba goes through much more power as its sending out a stronger signal. It also has an LCD screen and much more functionality so I think just stick to the stock setup or buy another TX RX.

    [​IMG]
     
  12. simonthk

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    Ok thank you I will consider that and I wont try to do stuff myself then :)
    It is a little more than I can pay now to get that upgrade, so I must wait.
    Thanks you again for all your info
     
  13. martcerv

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    The only other possibility would be using some sort of WiFi booster to boost the signal, but unless your planning on doing longer range flying then the stock tx rx is ok for inside 600m LOS where you shouldnt have any issues. If you dont want to spend/loose money on a better radio setup do you really want to be flying your phantom to longer ranges on an untested DIY setup that could fail and lose or destroy your entire setup. :?:
     
  14. simonthk

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    That is very hard to say. The question is also, if I have the money for the futaba and what the alternative cost. Also how much it is approved by others, which it seems not to be at all. Also I have a cat that is sick xD bye 500$