ALTA 8 FPV signal problem

Discussion in 'ALTA 8' started by Taki Darendeli, Jan 14, 2019.

  1. Taki Darendeli

    Taki Darendeli New Member

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    Hello Freefly Forum. I'm having some problems with FPV signals. The FPV signal is disconnected, usually at a distance of 480 meters. Sometimes there are serious parasites before they even reach this distance. Sometimes I need to fly the Alta 8 at a distance of 700-800 meters. I don't want a booster for the FPV transmitter. Because it requires extra cables and a separate battery. I've already replaced my antennas with pagoda antennas. The quality of the signal has increased a bit, but the distance has not changed much. I am using Lilliput FPV monitor. I wonder what is the best solution to increase the antenna distance. Waiting for your advice.
     
  2. Rolands Zelders

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    Hi, Taki.
    Have been dealing with the same issues. You haven't mentioned what kind of transmiiter you are using and most importantly what is transmitting power for the TX. I would suggest to look for TX with 800 to 1000 mW.
     
  3. Taki Darendeli

    Taki Darendeli New Member

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    First I apologize for my late answer. I read the answer yet. I ordered the Fpv system from Freefly when ordering Alta 8. On the Drone, Boscam has a 600 mW power fpv transmitter. https://hobbyking.com/cz_cz/boscam-5-8g-32ch-600mw-wireless-av-transmitter.html?___store=cz_cz

    5km distance on the website writes. But I've never passed 480 meters. I use this antennas https://www.amazon.co.uk/Antenna-5-8GHz-Circular-Polarized-Crazepony-UK-As-Shown/dp/B06Y6875BT

    I use this FPV monitor Lilliput 339/DW 7 https://www.bhphotovideo.com/c/prod...Tmi_XgRadoVPOtyEIC73nKi5zThXohx0aAjzeEALw_wcB

    I don't know where I'm wrong. I'm not very knowledgeable about FPV. Would it be useful to use the receiver of the fpv system instead of using the monitor's own receiver and connect it to the monitor via HDMI? Does a gimbal and Amimon connex transmitter under the Drone have a serious negative effect on the fpv signal? I'm waiting for your help
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Could you post an image of your ALTA showing the placement of the transmitter and an image of your receiver, also showing the placement of its receiver please, Taki?

    Thanks
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  5. Taki Darendeli

    Taki Darendeli New Member

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    Since I've been away from the office for a few weeks, I'm returning now. I'm uploading photos. I hope that has been revealing. If you need any further information, I will forward it here as soon as possible.

    [​IMG]


    [​IMG]

    [​IMG]
    [​IMG]



    Thanks
    Taki
     

    Attached Files:

    #5 Taki Darendeli, Feb 13, 2019
    Last edited: Feb 13, 2019
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Taki:
    Hmmm. I'm not seeing the images. Did you upload the files and then select thumbnails or full size?

    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  7. Taki Darendeli

    Taki Darendeli New Member

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    You can see now. Thanks :)
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I presume the FPV transmitter on the ALTA out on the right where a hand is visible in the last image?
    It looks to be pretty well clear of everything -- and even though the antenna is circularly polarized my understanding is that it doesn't matter if the one on the ALTA is inverted but those on the monitor are upright.

    I would start to suspect that there is electronic noise seeping in to the camera or the transmitter -- I'd start with the transmitter first. The way to reduce the noise (it only reduces, not eliminates) is to get a ferrite ring and thread the wires heading out to the transmitter through the ring several times. See the first image on this page: https://forum.electricunicycle.org/topic/6479-smoother-acceleration-esc-ferrite-rings/ (yeah, I know the ALTA's not a unicycle, but it's a good image! :) ).

    Hope this helps
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  9. Taki Darendeli

    Taki Darendeli New Member

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    The other issue I was wondering is, how far are the Alta pilots receiving the fpv signal without any problem? I'll be happy if you share your experiences.
     
  10. Rick Gerard

    Rick Gerard Active Member

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    I get 400' to 600' no matter which antennas I use or how I mount them using a https://www.flysight.com/flysight-black-mamba-tx-v-31.html

    The Black Mamba TX is supposed to have an open range of "9000m at open area without any obstacles" according to the documentation but I have never been able to get anything close to that even from maximum altitude. I have tried diversity antenna receivers as well as simple Spektrum single antenna receivers. I'm going to give the ferrite bead idea a try. My Teradek Bolt 500 flying on the Alta has about the same range.
     
  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Part of the technical/physical challenge is that the MoVI gimbal is made up of carbon fiber and it's conductive (to some degree, depending on the type of CF used) and absorbs some radio frequencies (again, depending on the type) so it can obscure the line of sight between the FPV transmitter on the ALTA and the receiver on the ground.

    But also, given that you have a "thing" flying in the air, there's no such thing as a "ground" that you can use to dissipate noise -- it's just the negative side of the LiPo battery. So if you get noise being injected it can come in along the positive voltage wire, the signal, or even the negative alleged ground.

    To make matters even worse, on the ALTA itself, the electronic speed controllers (ESC) used for each motor have to switch high currents and that doesn't help in the slightest (that's British Understatement -- if you wanted an electrically noisy system a good choice would be an ESC switching tens of amps driving a three phase motor!). So the FF engineers really work hard to minimize noise and improve reliability. I say that not as an FF employee -- I'm just a volunteer -- but I've visited FF and I've been impressed by how much time, money, and effort goes into design, build quality, quality control, and testing.

    Bottom line: Dealing with electrical and RF noise is out there some where between science, art, and voodoo.

    I realize that the above does help solve the problem -- diagnostically it's tricky and you may find that you have a bad FPV transmitter, or dodgy FPV receiver, or both (yeah, it happened to me -- not from FF, I hasten to add, but from "another vendor." :) ).

    Please keep posting so the community can learn the results of your testing.

    Cheers
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
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  12. Rolands Zelders

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    With boscam 600mW I have flown over 1300m on a clear ground with antenna facing reciever, but facing away it dropped to 700..800m.

    Flying in city it's another story. Switch to more powerful transmitter, skyzone 2000mW, for example
     
  13. Rolands Zelders

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  14. Taki Darendeli

    Taki Darendeli New Member

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    Yeah, now I realize that this info is not a distance. Thanks
    As far as I understand, you can get an average of 750 meters of video signal with the systems we use. We can receive signals up to 450 meters. I'm still not sure where we're doing wrong. But so far the most logical solution is to change the transmitter. I think the only suggestion in this is the skyzone 2000mw. Anybody test this transmitter? I don't want to drop other signals while boosting the FPV signal. Which transmitter can best provide the best combination? I will be very happy if the experienced users share their experiences.
     
  15. Rolands Zelders

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    try change a channels for your fpv
     
  16. Taki Darendeli

    Taki Darendeli New Member

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    Which channel should I use? I didn't know the channels could affect the signal quality.
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Taki: There may be radio frequency interference on certain channels, so you may find that other channels have less interference. It varies from location to location, so you may just have to experiment.

    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  18. Daniel Waghorne

    Daniel Waghorne New Member

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    I was having this issue until I swapped antennas to the Aomway ones I'm currently using. Clearest signal I've ever had. Joshua Bardwell has a great video on youtube trying out different antennas and showing which ones work best over distance/through obstacles, and these beat out every other antenna on the market. The only reason he didn't recommend them is that he's flying racing drones and the exposed metal has a higher tendency to break when crashing a lot. Hopefully that changes a bit when referring to the Alta :)

    https://www.amazon.com/gp/product/B01MR4X7GQ/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
     
  19. Taki Darendeli

    Taki Darendeli New Member

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    Thanks for all info and advice.
    I'll try this solution also. Thank you for your sharing.
     
  20. Rick Gerard

    Rick Gerard Active Member

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