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GPS shielding fix broke my bird :(

Discussion in 'Phantom 2 Vision + Discussion' started by kirbinster, Sep 23, 2014.

  1. kirbinster

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    So I had a fly-away the other day that I posted here, and I think I have figured out what caused or at least contributed to it. I never had an issue with my bird, but put the GPS antenna wire under the shielding as many here had suggested. I noticed today that it took a very long time to get a GPS lock, while I never had that issue before. After about a five minute wait I finally got GPS lock and had 8 sats at take off and once in the air it held at between 9 or 10 birds. The problem now is that when I turn on the video it looses GPS signal below 6 and the icon on the phone greys out. As soon as I turn the camera off it goes right back to full signals. So, is it possible that there is a spot under the shield where the wire may actually be picking up more noise rather than less.

    I am thinking of taking the wire back out, as I cannot use the camera at all the way it is. Would it be worth using aluminum tape to just encase the wire outside of the shielding to act as a shield on just the wire. I am upset that this fix seems to have broken my bird that was working fine before the "fix" :(
     
  2. ilovecoffee

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    Make sure none of the metal from the shielding is exposed? You should cover it with electrical tape or another insulator so it doesn't accidentally come into contact with any of the parts below. This is assuming you put additional shielding, and not just ran the cable under the existing shielding. If you just ran the cabling under the existing shielding than I am not sure what could be causing the issue.
     
  3. kirbinster

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    I just relocated it to under the installed shielding, did not add any metal. Maybe where I have it coming out from under the shield is close to a wire for the camera?
     
  4. dpdpkpcom

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    I would suggest using copper tape as the shielding and what I think may I be KEY is to wrap copper (or aluminium) tape around the extruding gps cable.

    Make sure you insulate it all so there are no risk of shorts !!

    Hth

    dp
     
  5. rrmccabe

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    Something to consider is satellites one day cant be compared to satellites the next. You really need to compare a solid week of flying to another week.

    I would try again before coming to a conclusion. And if its still bad try moving the cable or maybe going over the top and adding the tape.

    Take pictures this time around :)
     
  6. kirbinster

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    Not sure I understand what you are saying. Before moving the wire the camera never had any impact of sat reception. Today I had 8 to 10 birds and the moment I turn on the camera it drops below 6. I did this several times and the results were the same each time. I don't see how that has anything to do with the sats themselves.
     
  7. rrmccabe

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    I misread the part about it dropping when hitting record. Sorry, my mistake.

    But I would try moving the cable or moving it back over the top of factory shielding and then covering with metal tape.

    However you placed the cable under the shield is obviously not working for you. Just need to tweak it a little.

    I did the mod and it worked great.

    As I said I misread your post. Sorry !
     
  8. kirbinster

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    No problem, just wanted to make sure I was not missing something.
     
  9. E_T

    E_T

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    Any luck getting it working again? I was thinking of trying this mod, but after reading stuff like this, I'm not sure I want to risk it.
     
  10. RipperFox

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    One thing I never here people discuss about shielding is grounding. The purpose of shielding is to inductively "absorb" electromagnetic signals and prevent them from affecting a signal on another conductor. This requires grounding.
     
    John N Kronyak likes this.
  11. N017RW

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    It has been mentioned, trust me cause I have (at least).

    But even so un-grounded will provide some attenuation as any item encountered will simultaneously absorb, reflect, and pass some degree of energy.
     
  12. John N Kronyak

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    I'm a Systems Electrician who works with shielding all the time. If the shield doesn't have a pathway to "Drain" it is effectively useless. The power supply is the only place to drain the interference in the case of a drone in flight.
     
  13. N017RW

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    This is simply untrue, i.e. the useless mention, at high frequencies.

    Suffice it to say the Windsurfer reflectors so popular here are ungrounded shields which effectively REFLECT the energy. Due to the parabolic shape they also shape the beam(s) creating gain (compared to an isotropic antenna).

    The same holds true for the GPS shields. They reflect the unwanted emissions away from the GPS systems created by the circuitry below it thus increasing the signal to noise ratio. In addition they provide enhanced ground plane which in turn can increase bandwidth.

    Besides, there's TONS of imperical evidence here to the contrary.

    When photons hit any material they are simultaneously reflected, absorbed, and transmitted (pass-thru).

    Grounding does reduce the last two but that is not needed or wanted in all cases.

    Edit: the grounding improves absorption and reduces transmission, wanted to be clear about that.
     
    #13 N017RW, Sep 23, 2015
    Last edited: Sep 23, 2015
  14. RoyVa

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    Very true. Proof... Put foil on back of a omi-directional antenna and the signal will be reflected to opposite direction... Foil not grounded. It's called signal bounce, redirection, and many other things but the key is it shields signals.
    Any shielding helps with noise.... Or interference from signal transmission. Look at Shielded coax cable. Shielded Cat 6 cable. They all help reduce unwanted interference from electrical so called noise from electronics producing signals or pulses. Shield it, it can't hurt!