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FPV transmitter on top off iOSD Mini or 2.4 GHz Datalink

Discussion in 'FPV (First Person View)' started by RCblog.nl, Aug 26, 2014.

  1. RCblog.nl

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    Hey guys,

    I am relocating my FPV Transmitter (Boscam TS353) so that the antenna will point out of the side instead of the back, to solve the issue of losing FPV video when the Phantom is facing the home point when flying back.
    I have an iOSD Mini and 2.4 GHz Datalink (Ground Station) mounted externally also (don't want to mount anything inside the shell), and the lack of space in this new layout requires me to stack the FPV Transmitter on top of either the iOSD Mini or Datalink, with a layer of double sided tape in between them.

    I just wanted to make sure: is this safe to do? E.g. won't the iOSD Mini/Datalink/FPV Transmitter interfere with each other in any way when being stacked?

    Thanks!
     
  2. SJBrit

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    What kind of antenna are you using? People often point them in the wrong direction. Mostly they need to be pointed straight down - mine runs down one of the legs which gives me the best 360 deg coverage.
     
  3. RCblog.nl

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    Circular Polarized 5.8 GHz tuned cloverleaf antenna. Pointing straight down from the back gives good reception up to 2 km, but when rotating to fly back at that distance I completely lose video.
    Friends have much better experience with that same antenna pointing out of the side.

    But my question was: is it safe to stack the vTX on top of either the iOSD Mini or Ground Station Datalink?
     
  4. SJBrit

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    The antenna pattern for the cloverleaf is like a donut with the hole in the direction of the feed. If you point it straight out sideways then your donut is vertical and oriented like a wheel. That gives you coverage in front and behind, and also above and below. That's not good since it gives you a big hole in coverage to the left and right - you'll lose signal flying with the sides pointing towards you.

    If you point it straight up or down then you have a horizontal donut with coverage all around 360 deg, but none above and below. That's pretty much optimum.

    Now you have to take other obstructions which will block the signal into account. A common mistake is to put the antenna in the rear at the center which I'm guessing is what you have - that way the camera blocks the signal when you are heading home. If you put it straight down and off to one side of the camera then one side is blocked, but you have coverage on the other side and both front and back.

    Better yet, get the extended landing gear and lower the antenna so it's below the level of the camera and oriented vertically (meaning a horizontal donut). That gives you unobstructed 360 deg coverage and is how I run mine. I don't get break ups in my video feed due to orientation - ever. 400mW 5.8 GHz with a cloverleaf up top, diversity receiver down below with a cloverleaf and a 13dBi patch.
     
  5. SJBrit

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    And yes, I realize I'm not answering your original question but I think you are asking he wrong thing. What you really want to know is how to mount your video Tx and antenna for best reception. Cut a strip of carbon fiber about an inch wide and run it from one front leg to the back leg on the same side. Drill a couple of holes and secure it with zip ties. Now attach your Tx to that strip.

    I'd post pictures but my Phantom is all set up for 900 MHz at the moment and everything is different.
     
  6. RCblog.nl

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    Well thanks for all the info - sorry to say, but info that I did not need.
    I am well aware of the signal pattern of the CP and like I said: friends have much better experience with that same antenna pointing out of the side. --> That is pointing straight DOWN but running from the side, clearing landing gear and gimbal. I have seen their signal performance first hand, now I want to copy that.

    But the difference in our setups is: I have the Ground Station Datalink under there too, so I am going to need to stack stuff on top of each other.
    So my question was: is it safe to stack the vTX on top of either the iOSD Mini or Ground Station Datalink?
     
  7. SJBrit

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    OK - gotcha. Just wanted to make sure you knew that you would have a null pointing out left and right that way.