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Best Mounting for DJI AVL58 vTx?

Discussion in 'General Discussion' started by splashproof, Oct 18, 2013.

  1. splashproof

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    Hello, I am considering attaching my DJI AVL58 Video Downlink Transmitter to the backside of the frame of my ZenMuse H3-2D Gimbal. I would use a heavy duty velcro patch and make sure that nothing interferes or touches the silver motor hub on the gimbal. It seem like this might work well with the antennae bending down from a horizontal mounting position. I would make sure that the vTx fan is clear as well. My concern is that the antennae (~1.2" away) or vTx metal frame (~2.4") may interfere with the compass. Any thoughts on this? Any other problems to anticipate? Is there a much better solution? I really appreciate your time!

    Cheers
     
  2. miskatonic

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    I have this transmitter and I mounted it with one of these: https://www.shapeways.com/model/126...-bracket.html?li=search-results&materialId=62 It works perfectly in this configuration and because it is using 5.8ghz it is not going to interfere with anything on the Phantom itself.

    Do not use Velcro! This is the 21st century and there are much better products. Use 3M All Weather fasteners instead: http://www.amazon.com/Scotch-All-Weather-Fasteners-Inches-RFD7090/dp/B00347A8EO/ref=pd_sim_indust_3
     
  3. martcerv

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    After a fair bit of trial and error I found this to be the best way to mount it.

    [​IMG] [​IMG]

    If it gets too close to the camera it gets some interference but its best to have it as far forward and low as possible so as not to get the camera or entire body in the line of sight when turning back towards yourself.

    Here is how I used to mount it below, but in this position when a long way away over 1km turning back it would get noisy and at longer range beyond 2km it would be a great signal on the way out but turning around would pretty much lose video when moving forward. If you imagine the pitch angle of the phantom when flying forward, having the antenna out the back with the back much higher then the front in forward flight. This will put the entire body in the line of sight and at long range this is enough to completely lose the signal.

    [​IMG]

    If you see the antenna position in the second pic even at full forward pitch if the camera can see straight ahead then the antenna still maintains LOS. Now the main issue is my Radio antenna is still on the rear leg and so gets the same issues when well beyond 1.5km away. Now the weaker link is again my Futaba 8FGS so I will need to find some way of moving this antenna forward and lower yet far enough away from the VTX to maintain max seperation.
     
  4. splashproof

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    How about with the H3-2D in place?
     
  5. martcerv

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    Guys just a warning abut hanging the gear too low, I managed to break both an antenna possibly (i threw it away after it stopped working and had some physical damage) and also just noticed I damaged my vtx. What happened is that I must have had it hanging a bit below the landing gear and during a small crash clipping the ground the vtx antenna got badly kinked on the white cable section. I did do some flights with horrible range and figured that I got the same range with antenna connected and no antenna which is what led me to believe it was just the antenna broken.

    I did get some IBcrazy bluebeam antennas as it was hard to get replacement DJI ones, I have ordered these but they are a few weeks away. I tried the new antennas but had the same crappy signal, I also noticed the sma socket had some slop in it so opened up the tx and noticed all the solder joints have been broken. So technically I had no antenna connection at all, it doesn't look like anything has burnt out in the tx but I am going to resolder it and try again maybe needing to buy a new tx if re-soldering doesnt fix this.

    At least it will give me a chance to compare range between the DJI cloverleaf antennas and IBcrazy Bluebeam ultras that are regarded as some of the best antennas by many RC guys.

    So positioning of the antenna is a bit tricky as you want it to be down low and prefereably forward to avoid being behind the camera or body at high forward pitch angles. Its pretty rare to fly high speed in reverse using FPV so not a big issue trying to avoid this attitude position. If flying high speed in reverse there is also little point in getting a good FPV signal as your not looking where you are going anyway. Just make sure the antenna is just above the landing gear to avoid damaging it or the TX on a hard landing or a ground scrape as I did.