Internal fitting of an ImmersionRC 25mW video transmitter

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Hi Guys,

I thought I would share my successful modification with you: the internal fitting of an ImmersionRC 25mW video transmitter into a Phantom 2.

There are a few reasons why I went for the 25mW version;
  • it is the maximum legal power available for 5.8GHz in the UK and Europe (unless I am in the majority who flout the law according to the BBC)
  • the lower power will lead to less current draw and longer battery life
  • lower power means lower heat making an internal fitting feasible
  • there is more to be gained with better antennas than more powerful transmitters
  • it was cheaper and I wasn't paying
  • as I will mostly be flying line-of-sight with FPV for framing, I don't need huge distances

Firstly, I did a few baseline tests against which to judge the final result. I fitted the DJI iOSD Mini internally, and attached the video transmitter to one leg with insulation tape. With stock antenna, and Black Pearl with stock antenna, I was able to fly over 700m without significant loss of video until I lost line-of-sight. Turning caused video drop-out as expected but I was still able to get 300m in any direction.
15962409868_344d4696d4.jpg
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Parts
Note :- Immersion use SMA connectors, not RP-SMA
ImmersionRC 25mW transmitter
4" (10cm) SMA Male plug to SMA female jack RF Coax pigtail
SMA Male to SMA Female 90 degree elbow
http://www.ebay.co.uk/sch/i.html?_o...0.TRC0.H0.Xsma+-rp.TRS0&_nkw=sma+-rp&_sacat=0

How to
1) Remove the lid (if you are reading this, you have probably done this before so don't need instructions!)

2) Remove the bolts holding the motors (all)
15962407708_7e080bbf87.jpg


3) Remove ESC screws. These hold the light covers on the underside, which will also detach. (all)
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4) Remove the four screws holding the main circuit board to the body. This also holds my Zenmuse anti-interference board
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5) Disconnect the front USB cable
15962404368_f65239d099.jpg


6) CAREFULLY cut through the silicone between the main board and the Remote Control receiver board underneath. The receiver cable is located close so take care.
16147939401_a669c0f44d.jpg


7) Remove the X1 cable from the controller. Remove the receiver plugs from the controller, note which plug goes where (not obvious without images to refer to)
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8) Remove the power connector
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9) I would completely remove the board at this stage, although I was hoping to do this without complete removal. You will find it easier if you do. (Note orientation)
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10) Dry fitting the transmitter.
16124064506_5ec6031cd0.jpg


11) Remove the fins from the front left. Leave something as this might be structural, although I don't think so, so I left the last fin.
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12) Remove the nut from the pig-tail lead and place as flat as possible, close to the power connector support. Use this as a guide. Drill the right size hole for a snug fit
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13) Attach pig-tail cable with washer and nut
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14) Loop the cable around and lay the transmitter in the gap created by 11). Place the hot part of the transmitter (with the sticker) against the side vents (every little helps)
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15) Transmitter in place
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16) Replace electrics and enjoy!

I was able to get just over 900m with this setup before the video became unusable. It keep dropping out over houses (WiFi?) but over fields was good enough to prove the installation worked. There will be some losses in the pig-tail cable, and wrapping the cable around the power lead, but hopefully some clover-leaf antennas and a patch antenna will help.

I will also monitor the heat given out, although at the moment it is just above freezing so might not become apparent until the summer.
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Nice install! Did yu make that pig tail cable yourself or purchased?
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Thanks phenom

The pig-tail and right angle were purchased from eBay (link given). I bought a few of different lengths, total cost was about GBP 5, including postage.
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Thanks, I completely overlooked the links!
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Nice one, very neat!

The only issue I would foresee is if you wanted to change the TX channel - to avoid interference etc. if flying with others. That's the only reason I have left mine on the outside of the quad.
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Good quality clear pictures for the instructions. I was considering something very similar.

viewtopic.php?f=4&t=32552

I am using a 400mW transmitter with heat sink, so was thinking of cutting out the fins to fit the heat sink to the outside for heat exchange. Was worried about the video transmitter causing/sending interference with the phantoms control reciever since they would both be inside the phantom.

Can you post a picture with the antenna on?

Have you flown it since this modification. Any issues? Thanks.
 
Re: Internal fitting of an ImmersionRC 25mW video transmitte

Here is the final setup with ImmersionRC 5.8GHz Circular Polarized SpiroNet Antenna V2 (SMA) fitted. The video transmission worked quite well, upto 900m which was the same as the stock antennas, so more experimenting is needed.

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