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Interference and Lilliput 339/DW issues

Discussion in 'FPV (First Person View)' started by KevinOBrien, May 21, 2015.

  1. KevinOBrien

    Joined:
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    Hi,

    I have a P2 V2.0 with a Gopro3 Black, a Zenmuse H3-3D gimbal, a 25 mW ImmersionRC transmitter, a Lilliput 339/DW receiver/monitor and TX/Rx antennas are Fatshark LHCP "mushrooms" with a LHCP Fatshark Patch antenna 13dbi. Internally, is a mini iOSD and the anti-interference board.

    I am happy with handling and flight time but the screen flickers even at short range (<50m). This is ok out to 200m then the picture starts to drop out and I get a lot of interference and snow. I took it out to 500m today and you could just about make out the picture but the quality was crap, tbh.

    The seller stated that the max legal transmitting power without a license is 25mW. So I went along with this as he stated also that with LHCP mushrooms and an LHCP patch antenna, I could get up to a kilometer!
    All I am after is a crisp, steady picture out to but not more than 1km. Do I need to up the transmitter power or change the antennas to helicals or something? I also have an older ImmersionRC 250mW transmitter and will test if this improves reception.

    The Lilliput monitor/receiver is also quite confusing. The manual is not very good or in-depth and it seems everything is automatic which makes choosing channels easier I guess, but which doesn't seem to follow any logic. There is a channel selector for each antenna with five little switches and when they are uppermost they are in the ON position. The variations are shown on the back of the monitor (32 channels) plus 8 DJI channels. Each channel has a 5 digit number, e.g. channel 7 (of the 32 general channels) is 5745. This is the same as the default setting on the transmitter itself. When I set everything up, I left everything as it was from the shop, i.e. on both antennas all the little tabs were set to ON. I scanned the channels using the AUTO button and it went through 31 channels showing good pictures on channels 7 and 25. I though that if I then selected those channels to be picked up by the antennas I would get the best signal. It doesn't seem to make any difference though. The transmitter also has these little tabs but only has 4 and only uses the first three. When I checked these little tabs they are in the 1(on), 2(on), 3(on), 4 (x), which corresponds to 5740 MHz or the transmitter's Channel 1 (according to the package). What's confusing is that channel 1 on the transmitter is channel 25 on the General channel list for the monitor/receiver and channels 2-7 on the transmitter are general channels 26-31 respectively. On closer inspection, the DJI channel 1 (5705) is the same tab configuration as channel 17 of the general channels, DJI channel 2 is channel 18 and so on until channel 8 is the same as the general channel number 24.

    Apologies for the essay here but does anyone have an idea what is the best way to set this up?

    Cheers,

    Kevin.
     
  2. KevinOBrien

    Joined:
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    Small update. Too windy to test flight today but it
    seems the Fatshark Immersion CP antennas I was sold are grey ones which were just listed as Spironet V2 antennas. Both are identical and have red flexible shafts with SMA connectors. Like these from Hobbyking:
    http://www.hobbyking.com/hobbyking/...SpiroNet_Antenna_V2_RP_SMA_EU_Warehouse_.html
    Apparently they are pretty good. I have checked from online vendors and these are all RHCP. The Lhcp versions from Fatshark are white and have lchp on them. The patch antenna I was sold is LHCP. So, is 200m ok range for a 25mW transmitter with these antennas? Should I replace the Lhcp patch? Is it worth just getting a helical instead, like the Aomway?
     
  3. thestone11

    Joined:
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    Location:
    Alberta Canada
    Aomway helical from hobby king is great! I have one on my black pearl monitor, together with blue beam ultras on the bird. With a 600mw transmitter, I have clear video feed from 1.2km out! My FPV out range my radio!