WEAK SIGNAL DIRECTLY OVERHEAD
973 12 2017-8-28
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Dublinphantom
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HI. I flew 120m directly above my head this morning and got weak signal and eventually aircraft diconnected RTH.
Is this normal?
I was in a built up area with a bit of interferance. Tried changing between 2.4 and 5.8 but it didnt make much difference.
Just want to know if this is normal for a P4P?

THanks

2017-8-28
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Genghis9
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Well Dublinphantom, important question...what were the position of your antennas?  I ask because that may very well be the explanation to your problem.  Antennas are somewhat directional, in that their coverage radiates out from their length wise sides, more importantly not out of the tips.  Therefore, if you were directly overhead and your antennas were pointing straight up, then you were operating your UAV in the cone of silence, meaning the area where you will get a weak signal.  This is just a limitation of the antenna design and not a flaw.  
You need to watch this tutorial video and it will explain it much better than I:


You may have experienced additional interference that compounded this situation too, I could not say.  I recommend you not fly directly overhead but at an offset angle and ensure your antenna are not pointing directly at your UAV when in flight.

Also I recommend you go here and review the other tutorials that will help you avoid other issues:
https://www.youtube.com/channel/UClH0xVO3zOfYdGjoPU6S2hw

Fly Safe and Enjoy!
2017-8-28
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Dublinphantom
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Hi. Thanks for the advice. I am aware of those points of no signal as I have a P3S too and have done a lot of research about antennas and their behavior . When it first happened I did push the antennas down so they were parallel with the ground but it didn't make a difference. When the drone lowered itself in RTH mode it eventually kicked back in. I was just a little surprised being a P4P that it lost signal at only 120m. it may have been the fact I was in an industrial estate though.
2017-8-28
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Dublinphantom
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Hi
Im wondering if this is related to the fact I updated the RC firmware but not the drone firmware.
I went into DJI GO4 and pressed the menu button for 10 seconds to enter the option to downgrade the rc firmware but in the dropdown box there isnt an option for the previous version, which I believe there should be.
Any idea how I can get hold of the previous version of rc firmware to downgrade it?

THanks
2017-8-29
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hallmark007
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Dublinphantom Posted at 2017-8-29 05:12
Hi
Im wondering if this is related to the fact I updated the RC firmware but not the drone firmware.
I went into DJI GO4 and pressed the menu button for 10 seconds to enter the option to downgrade the rc firmware but in the dropdown box there isnt an option for the previous version, which I believe there should be.

You really need to go to an open area and test , this will narrow things down for you.
2017-8-29
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Labroides
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Completely normal.
You get optimum signal when the antennas in the controller and Phantom's legs are parallel and facing each other.
Flying straight up, whatever you do with your antennas, you will always have trouble maintaining good signal.
The higher you fly, the harder it is.
It simple geometry.
2017-8-29
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Aardvark
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Remember the antenna in the legs are sitting in a vertical position. Ideally the antennas in the aircraft and the RC should be parallel to each other. Although the antenna on the RC can be rotated for better performance, the ones on the aircraft cannot. So the aircraft being directly above you is the worst possible location for it in terms of reception and transmission of data.

It may well be that the latest RC firmware does not give best operation with the previous aircraft build.
You should be able to roll back I would think, provided that your display device has a good internet connection. I certainly have that option available on my P4 RC.
2017-8-29
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Dublinphantom
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Aardvark Posted at 2017-8-29 05:36
Remember the antenna in the legs are sitting in a vertical position. Ideally the antennas in the aircraft and the RC should be parallel to each other. Although the antenna on the RC can be rotated for better performance, the ones on the aircraft cannot. So the aircraft being directly above you is the worst possible location for it in terms of reception and transmission of data.

It may well be that the latest RC firmware does not give best operation with the previous aircraft build.

Thanks that explains the signal loss directly overhead. it makes sense.
In regards to rolling back the RC firmware, I know how to do it through the app by pressing the menu button for ten seconds etc and selecting the older one on the dropdown box. My issue is in that dropdown box is only one listed which is the one I currently have. nothing older, yet I did update it on Sunday. the version I have installed is 01.04.01.00 and thats the only one listed in the dropdown box. Any ideas why? I was connected to the internet too.
2017-8-29
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Aardvark
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Dublinphantom Posted at 2017-8-29 05:46
Thanks that explains the signal loss directly overhead. it makes sense.
In regards to rolling back the RC firmware, I know how to do it through the app by pressing the menu button for ten seconds etc and selecting the older one on the dropdown box. My issue is in that dropdown box is only one listed which is the one I currently have. nothing older, yet I did update it on Sunday. the version I have installed is 01.04.01.00 and thats the only one listed in the dropdown box. Any ideas why? I was connected to the internet too.

There is a possibility that roll back is not available on the P4P versions. Somebody else with a P4P should be able to confirm that. There were several previous versions.
2017-8-29
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Dublinphantom
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But the option to go into that section in the app is there. Funny they would not allow it go any further. Im afraid now I have to go ahead with the AC firmware which I was trying to avoid. But to keep them both in sync I should really have one firmware that belongs with the other or does that matter? it does occasionally warn me i have two incompatible ones, but still flies.
2017-8-29
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Howie12
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You can't roll back the data on P4P through the DJI website.  Someone suggested doing a google search to find the older software.
2017-8-29
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DJI Susan
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Agree with 2#. Adjust the antennas, you will get better signal.
2017-8-29
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Kneepuck
Second Officer
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Because the antenna are in the landing gear, they are oriented like this : |      The antenna on the rc, if parallel to the ground are  : - .  If pointed as normal, they are | .  So, you can see that directly overhead, you are getting minimal signal no matter how you orient antenna on r/c.
2017-8-29
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