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Antenna suggestion needed

Discussion in 'Phantom 2 Discussion' started by voodoo, Mar 19, 2015.

  1. voodoo

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    Hey,

    My new P2 with Zenmuse and fpv is working great. When I go to very secluded areas, my video feed is perfect. I run a Hero4 black with immersionRC 600mw Tx and circular polarized fatshark antenna (curved down to face ground). As a Rx, I have a 7" blackpearl with one circular polarized fatshark antenna which faces up, and I have linear stock 5.8Ghz antenna pent at 90 deg to the ground as secondary. When I fly at a smaller park near my apartment, the feed is pretty weak, as I believe the condo building nearby has lots of interference. However, this is strange to me bc my video si 5.8Ghz?

    Regardless, I never want to have spotty fpv signal / feed inside of 500m or as far at 1KM. I see people using big heli antenna and plate style things - if I want to upgrade one or both antenna, what is suggested. I'd be willing to pay up to $100 on something probably. Cheers.

    1) If I want to upgrade one or more antennas on my monitor for stronger video feed, what style antenna would you suggest? I get super strong signal when secluded, and spotty feed in some locations.

    2) What is the best orientation for the antenna on the video Tx on the UAV - sideways or downwards / bent downwards? I have mine on the rear of the drone, facing backwards, and curved down towards the ground.

    3) Please confirm - I am pretty sure the best orientation or the RC transmitter antenna is sideways, parallel with the ground?

    4) If I would like to upgrade my RC transmitter to something with top tier reliability, what would you suggest that would give me a performance boost but not be top of the line / bank breaker?
     
  2. TeamYankee

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    It's probably interference from 5.8Ghz wireless signals, nearly all mobile phones produce 5.8Ghz noise along with dual band wireless access points. Not to mention point to point CCTV units...etc, etc
    As a starting point.. switch your phone to "aicraft mode" to kill all radio noise as it's the closest 5.8Ghz signal to your receiver.

    Your FPV antenna placement seems about right.. although when flying back towards you the GoPro or Gimbal can get in the way and reduce the FPV range... use a longer antenna lead on the FPV tx so it stick down lower than the camera..
    hand catch it when you land.

    The best option would be to use something like this instead of the standard vertical antenna on your diversity receiver:
    http://fpvlr.com/shop/index.php?route=product/product&path=77&product_id=59

    The longer the antenna the more gain.. but then it gets highly directional and you have to keep it pointed towards the Phantom to maintain the link.
    For example this one:
    http://fpvlr.com/shop/index.php?route=product/product&path=77&product_id=62 Not recommended unless you know what you are doing!

    Make sure you use the correct connector and the correct polarization on the FPV TX and the RX.

    With regards to the RC transmitter.. this should be vertical - ie. the same orientation to the receive antennas on the quad.

    Hope that helps...
     
  3. thestone11

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    [​IMG]

    I used to run two spironets on my back pearl, I am getting good signal up to about 300m away. I upgraded one of them to an immersion rc patch antenna, now I am getting excellent video feed all the way up to 1km. Once in dense residential area, I lost my Radio signal after 800m, but video feed is still going strong. Only thing you need to know is patch antenna is more directional, you have to point it to the phantom at all times to get the best result. It transmits only in 30 degree angle.

    And for the phantom, I just run a spironet.
     
  4. QYV

    QYV

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    hi Voodoo. Yankee's suggestions are good, although there's no way you need that 12 turn helix. I don't have any experience with those new "plate" style antennas like thestone has but my setup is easily 2km or more rock solid.

    imo, a good antenna and proper orientation on the Phantom is essential. I think the best antenna you can get for the transmitter is the FPVLR Pentalobe, which is part of their premium combo.
    ANY transmit antenna position that doesn't hang below the gimbal & legs of the Phantom is going to have dead zones. I personally put a 90degree connector on the pentalobe so that the lobe now hangs down 1-2 inches below the Phantom. Yes, this means I always have to launch from a ledge (or hand launch) but I never have any dead zones during flight. I've been out over 1800m and my FPV was as solid as when it's right next to me, regardless of Phantom orientation.
    If you aren't willing to have it hang down like me, it'll still work you just need to be aware of your dead zone. Folks that hang the FPV antenna to the side for example have a big dead zone when the Phantom turns and the antenna is facing "away" from the pilot.

    So now that you've got the best antenna and positioned it ideally, we can talk about receiver antennas. The FPVLR premium combo I mentioned before comes with a pinwheel (omnidirectional, shorter range) and the 4.25 turn helix (long range, directional) that Yankee linked above.
    When you're talking about helix antennas, the more turns the more range but the more precise you have to be aiming it at the Phantom (the FPV transmit antenna, technically). 12 turns is too much, you have to be SUPER precise and it's just not necessary. the 4.25 turn is a great balance of range (he claims it's a 10k antenna) and you don't have to be crazy precise with it, although you do have to keep it pointed generally at the Phantom.

    I have a 400mW TS353 transmitter, and with ONLY the pinwheel receiver antenna I can get around 650m before the FPV signal starts breaking up in a zero-interference environment. urban / high interference environment will obviously be less range.
    When I switched to the helix, I was solid out to 1800m and I only stopped there because it was my first super long range run, the helix should be fine out several more km basically exceeding the operational range of the Phantom itself.

    You mentioned spending $100 if you had to... I'm saying that $120 premium kit from FPVLR will give you FPV capability exceeding the range of your Phantom itself. unless of course you **** up the transmit antenna orientation ;)

    you could then sell your existing antenna pair and recover a little bit of $
     
    Toddzilla likes this.
  5. voodoo

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    Yes I will start switching my phone to airplane
    Should the antenna on the quad be facing parallel to the ground or curved and bent down to be pointing towards the ground?

    What does this mean? "Make sure you use the correct connector and the correct polarization on the FPV TX and the RX." I have no idea what this is referencing.

    And by this, do you mean the antenna on the RC transmitter should be pointed vertically? "With regards to the RC transmitter.. this should be vertical - ie. the same orientation to the receive antennas on the quad."

    Thank you
     
  6. Hughie

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    Two separate things which affect how an antenna works and how it fits to a receiver or transmitter. Google
    LHCP v RHCP
    and
    RP-SMA v SMA
     
  7. voodoo

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    Ok cheers. What about this part

    "Make sure you use the correct connector and the correct polarization on the FPV TX and the RX."
     
  8. Hughie

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    Again.
    Two separate things which affect how an antenna works and how it fits to a receiver or transmitter. Google
    LHCP v RHCP
    and
    RP-SMA v SMA
     
  9. deepeshdotcom

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    I have the same setup but I am using patch antenna to right side and getting only 200ms? does putting patch on right or left affect the distance? I only have 25MW Imersion RC video Transmitter. Does anyone know whats the max distance you get with 25mw VTX?
     
  10. Luap

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    I explain here how I set up the antenna on the Phantom so that at any orientation I have no video signal loss (If I flew inverted I'm sure it would not work)
    Phantom videoTX mount.
    Might give someone some ideas.