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Long range tests - No Signal during RTH

Discussion in 'Standard/4k Discussion' started by finalfantasyfan, Feb 28, 2016.

  1. finalfantasyfan

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    Today I was doing a few long range tests with my P3S with and without windsurfer.

    1st(Normal antenna): 7800 feet. Signal lost and RTH triggered. Signal was completely lost during RTH. I was worrying for a few minutes until it reconnect when it was 2400 feet away during the RTH. I turned the phantom around and sent it away for another range test. This time with Windsurfer on.
    2nd(Windsurfer): I initiated RTH when it fit 9700 feet because of the low battery level. This time again, right after the phantom turn around, Signal was completely lost again until around 2400 feet again.
    HealthyDrones.com - Innovative flight data analysis that matters

    3rd(Windsurfer): I changed the battery and send it out for another test with windsurfer on. This time I let it keep going until 12580 feet when RTH triggered. Signal was completely lost on the way back until 6000 feet away this time.
    HealthyDrones.com - Innovative flight data analysis that matters

    Can someone explain why signal was lost in all these long range test during RTH? BTW, video signal was very good without any drop during the outbound flight.
     
    #1 finalfantasyfan, Feb 28, 2016
    Last edited: Feb 28, 2016
  2. finalfantasyfan

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    Anyone can know what's wrong. I created a video of my 3rd flight
     
  3. SZNJ732

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    I dont think there is anything wrong.. Mine is the same way. If i go out to 5,000', lose signal and trigger RTH, I usually cant pick the signal back up and reconnect until its back to around 1,500'-2,000' feet. i think its because technically it is easier for the bird to maintain existing connection link at long distances, but once it drops, its a lot harder for it to find that signal and re-establish connection again... Very good distance for standard btw, without using any mods...
     
  4. finalfantasyfan

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    Thanks. Still have many things to learn on my Phantom. Good to know that it is normal. But it was really scary when signal lost for 5-6 minutes.
     
  5. Bob8619

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    Did you have to toggle the switch to return to home or did it do it automatically? I"m just trying to figure out if you are losing all signal at the same time or losing video signal first. By video signal I'm referring to the signal being sent from the Phantom to the controller.
     
  6. Bob8619

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    This is for my own curiosity, what you described about not regaining signal right away is normal in my experience also.
     
  7. Klnyc

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    Yeh happened many times. I just wait for the bird to come back and 99.99% it comes back. One of these day maybe not.
     
  8. finalfantasyfan

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    I didn't initiate the RTH myself. It was automatically triggered. In fact, it didn't say RTH triggered on the phone which normally it does when I was doing closer range test before. It just lost all signal suddenly.
     
  9. Bob8619

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    So you seem to lose all signal at the same time as opposed to losing video but still having control.
     
  10. finalfantasyfan

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    Yes. Both Video and control was good on the outbound flight and then all signal dropped at the same time suddenly. I wonder if there was any strong interference near that area.
     
  11. finalfantasyfan

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    I don't know how to read healthdrone info. Maybe someone can help me understand it.
     
  12. SZNJ732

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    It looks like you had strong radio or wifi interference right in the middle of the lake on the way back (in the middle of the lake?? strange, no? maybe flying over a boat with a huge antenna?)...
    That interference most likely prevented your drone from reconnecting to your RC sooner. Once it got closer, your RC signal was strong enough for your drone to pick it up and re-establish connection.

    HD2.jpeg
     
  13. finalfantasyfan

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    Thanks SZNJ732. What does "Mode changed to 127" mean? How do I know at what point I reconnect the drone from the log?
     
  14. SZNJ732

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    You are brave for doing 2 range test on the same battery, over water!... From my experience RTH speeds are way below average flying speeds, especially if you encounter head winds.
    If you are doing 25+mph (your Healthy Drone shows top speed of 38mph!!) on your distance flight, get down to 50% battery, lose signal, now you are 12,000' from home, your RTH kicks in, and takes your bird back for a sightseeing ride, at a nice n easy ~7mph cruising speed, there is a good chance you won't make it, and it will auto-land somewhere over the water! Almost happened to me over the weekend. I was in RTH and when i got my video signal back, and my bird would not go over 7mph , i had it pedal to the metal, she couldn't care less. The Go app blaring low battery alarm, and im still 500' from home. Barely made it. A very nerve-racking experience.
    Just be careful and keep an eye your battery and wind!
     
    mdowney58 likes this.
  15. SZNJ732

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    Mode 127 is some internal DJI code. No official DJI explanation as far is i know. It is related to weak signal, right before or after losing it... I think it has something to do with your drone looking for stronger signal, both RC radio/wife and GPS, and trying to figure out what to do next, (look for GPS path back home, hover, etc)
    I usually see it when my phantom is far from home at in range limits..
    Its not always easy to tell where you lost your signal just by looking at Healthy Drones.
    Usually it would tell you something like this:
    05m 02s 284.4 ft 12,579 ft Mode Mode changed to 127
    08m 20s 283.8 ft 6,647 ft Data Loss Downlink data connection lost for 194.6 seconds
    It tells you how long you were without a signal. You lost it at 5m 02s, and got it back at 08m20s.
    You can also look at the yellow path track line in the DJI go app under Flight Record. When you hit play button you can follow the path, and see you red drone mark jump from say 10,000' / 10min flight time, to 5'000 / 8min flight time, this way you know you lost signal at 10,000' and got it back at 5'000...
     
  16. finalfantasyfan

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    Thanks for the advise. I got about 70% battery level after the first range test. So I think I can do another test(Assuming 10% used on outbound and 20% used on inbound) It was about 57% when it hit 9000 ft on the 2nd range test and I initiated RTH myself. When it came back, it still got 34% battery. From the DJI Go Flight record, the RTH speed was about 22mph after I reconnect to the drone. I will be more cautious on battery level next time when I do range test.
     
  17. RodPad

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    Yes, with above scary over water, distance, battery and wind. Look at your calculated winds on H.D. If the Average was like the Gusts. You could have spent Sunday in a boat.
    ;)
     
  18. Alan Russel

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    Hi Pilots..I flew my P3s this morning..did a range test and it was my Personal Best got out to 2201m (1.5 miles) had a tailwind so it took a while to return home..had windsurfer on remote!