Unwanted Return To home

Discussion in 'ALTA X' started by JoshuaDunn, Dec 23, 2019.

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  1. JoshuaDunn

    JoshuaDunn New Member

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    Hey all, its been an age since I have posted, as everything I own has been behaving so well.
    I have done two jobs with the Alta X and I am super impressed with the flight charateristics and handling, on both projects there was wind and light rain and aircraft and boats and all sorts of hazards, The X was amazing....... Until it decided to do a RTH on me a few times, Not ideal when your not expecting it.
    I had plenty of power left, only 5 minutes into the flights, the wind was factor but only blowing 40-50kph, payload was 10-12kg excluding batteries. I was above 400 feet AGL on all three occasions when it happened, So I am thinking this may be a factor, does the flight controller have some kind of safety thing build in when surpassing the golden line of 400? I had Notams in place, was in direct contact with the tower and had done all my homework legally, but just wondering as I am not familiar with this new controller.
    I was about 300m out horizontally, so defo not beyond the range of the remote. Any ideas anyone?
    Is there some parameter I need to change out? I loved the Alta 8 and its nifty App, its taking me a wee while to get my head into the QGC world. Thanks in advance to anyone that can help me out. Josh
     
  2. JoshuaDunn

    JoshuaDunn New Member

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    So I heard from Freefly support and it sounds like my on board monitor may be blocking my aerial on the top of my remote, The machine only does an unscheduled RTH when signal is lost, so its sounds like thats my issue. I will keep testing it without a monitor and see if it improves.

    Cheers, Josh
     
  3. Jason Smoker

    Jason Smoker Active Member

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    josh can you take a photo can people can reference what u saying thanks
     
  4. JoshuaDunn

    JoshuaDunn New Member

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    This is how I usually have my remote set up when flying the Alta 8 and X, I will now be running the FPV monitor off my remote as when I am flying at altitude I tend to tilt my remote up to remain in line of sight and still be able to glance at the monitor. This may be why I am losing signal, the monitor is quite solid and has a battery on the back.
    Cheers, Josh IMG_3080.jpg
     
  5. Jason Smoker

    Jason Smoker Active Member

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    i think that tg14sg antenna need to have more coverage its half covered by your monitor which is causing the radio to drop signal and the further you go the worse it gets. When you facing the drone you antenna is covered which is causing the unwanted return to home
    If you move that monitor up and over the antenna and make sure its clear the problem should go away
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I agree with Jason -- not only is the monitor shielding the signal to the the ALTA, but it will likely be a strong source of radio frequency interference. You need to have a unobstructed line of sight between between the 14SG antenna and the aircraft.

    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. Rolands Zelders

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    i have seen some guys have been using even longer antennas, but how well they work don't know
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    As long as the antenna is tuned for 2.4 Ghz, a longer one will work better. The typical transmitter antennae are 1/4 wave (that is they appear to the transmitter as an antenna that is 1/4th of the wave length of 2.4Ghz -- the full wave at that frequency is 12.5 cm). The thing that sticks out of the transmitter is likely mostly coaxial cable with the last 3.125 cm being the antenna itself.

    If you can replace the antenna with a 1/2 wave that would be more efficient, but keeping direct line of sight between the transmitter antenna and the receiver(s) antenna(e) is a Really Good Thing. :)

    Also, imagine a doughnut parked on the end of the antenna with the antenna tip sticking into the doughnut hole. That doughnut represents the directions in which the radiated signal is coming off the antenna (technical these are called the side lobes).

    Thus, if you have the antenna pointing directly away from you (horizontally) then most of the radiated power is heading straight up, left, right, and down. You need to have the antenna vertical so that the doughnut of the radiated signal is horizontal or even the antenna pointed back at you slightly so that the furthest away side lobe is "pointing at" the aircraft when you're flying it.

    Joshua's image shows the correct antenna orientation for maximum range (well, it would be if the monitor wasn't acting as a Faraday shield and absorbing most/some of the radiated signal! :) ).

    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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  9. JoshuaDunn

    JoshuaDunn New Member

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    Thanks for all the info guys, I tested without monitor and no RTH issues to date, My next job is in a few days, hopefully all is well.
    Regards, Josh
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sounds like you may have solved the problem, Joshua. Please post again if you're still having issues. Just issues with the ALTA of course.... <evil grin>

    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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