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FPV - learning and expanding, need comments please

Discussion in 'FPV (First Person View)' started by voodoo, Mar 10, 2015.

  1. voodoo

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    Guys,

    I've been flying a P2V+ for nearly a year and recently upgrade to P2 with H4B and fpv. I'm flying with 7" blackpearl and two fat shark circular polarized along with one stock 5.8Ghz antenna (one circular on the P2, one circular on the monitor as main antenna, and then the third antenna is a stock one an second on the monitor). See a crude diagram of the setup here [​IMG]

    I'm having issues with video range and performance and wondering if people wish to comment on the symptoms and positioning of my antennas? Thanks!
     
  2. Joesrevolution

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    Hi voodoo,

    From what I can see there is nothing wrong with your antenna positioning. When you say poor range, what numbers are we actually talking about? Also what video transmitter are you using? And what version of the black pearl? There are loads of reported issues with immersion/fatshark transmitters not working with the 32ch version of the black pearl. To fix this you either need to change out to the 7ch black pearl, change to a different brand of video transmitter (boscam, flighsight) or use an external receiver on your black pearl which is what I opted for.

    Other causes may include leaving the antenna off the transmitter. If you power up a video transmitter without an antenna attached all of you mw will escape meaning you will be extremely down on power. If you think you have done this a new transmitter may be in order I'm afraid to say.

    Next thing to check is whether your black pearl is diversifying properly (is that even a word...?) some times a receiver is a bit dodgy and if its biasing itself towards the left receiver (on which you have your linear antenna) you wont get desired range as circular and linear polarisation do not work too well together. Try swapping the antennas over on the black pearl.

    Finally where exactly are you flying? If you are in a built up area with lots of wifi signals your range will be reduced as the signals slightly interfere with each other. Not to the extent that will cause dangerous operation but it will reduce your range.

    Hope this helps, if anyone feels I've missed anything feel free to correct me ;)
     
  3. KraigNC

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    In "Joesrevolution's" post he says "If you power up a video transmitter without an antenna attached all of your mw will escape meaning you will be extremely down on power."

    I had my transmitter antennae fall off during flight. I didn't realize that it had come off until I landed. I put on a different antennae and I am getting reception so I'm thinking no damage done. Based on the comment I'm questioning if that is true. Is it possible for the transmitter to be damaged but yet still work just weaker? I have been out over 1000 meters and still have reception. Not without static though. I'm now wondering if I should buy a new transmitter.
     
  4. wkf94025

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    OP's diagram looks right, though I would replace stock whip on LCD with $20 patch antenna on 2" flex extension, and point that toward P2. I am using antennas and goggles listed below and went 2.5km this morning with perfectly good video in goggles out and back. At turnaround, flew backward, keeping P2's CP antenna toward me until <2km out, then spun 180 and came home forward. IRC VTx and Fatshark goggles, with Spironet CPs and a $20 patch are kitten's mittens. Can't speak to BlackPearl issues. I use IRC duo to power Lilliput LCD if I want screen feed beyond 1km.

    Of course on all such flights my acute 20/20 vision kept the bird in direct LOS at all times.

    Kelly
     
  5. Joesrevolution

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    KraigNC, its very transmitter specific. Some may be fine for long periods of time, some may not. Essentially if you don't have an antenna the rf power is converted into heat. Now if your transmitter has a heat sink it is much less susceptible to this kind of damage. However something like an immersion has no heat sink at all so they may heat up and fail very fast.

    Think these guys explain it better.
    http://fpvlab.com/forums/showthread.php ... at-happens

    +1 to wfk94025

    Buy a patch or other directional and do away with your linear.
     
  6. KraigNC

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    Thanks for responding and supplying the link. It was very helpful. I have an Immersion 600mw transmitter which was listed as one of transmitters that can run for a short time (a minute or so) without burning up. If that happens it may still work but with degraded power output. Based on this I've ordered a new transmitter. I suspect this may be why my reception is not as clear when I'm out 1000 meters as some other people seem to get using the FPVLR antennas.
     
  7. voodoo

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    Thank you everyone for comments. I am using an Immersion 600mw video transmitter and Black Pearl 7", I believe it is 32 channel. It's brand new, so I believe this is the one. I hope there isn't actually some compatibility issue with these two components. I get okay signal in some situations, and worse in others. I cannot go more than a 100m before I start to get serious static though?

    Maybe I did calibrate the P2 without antenna on the video transmitter, but I am not positive. How can I be sure I didn't mess it up??
     
  8. QYV

    QYV

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    What you just described IS precisely the "incompatibility issue" everyone talks about around here regarding the IRC600 and Black Pearl 32 channel... you just get no range before the signal goes out, there is no logical explanation for why they don't perform well together, and the type of antennas used seems to be irrelevant.

    Your choices are either swap displays to a BP 7ch or RX-LCD5802 (sell your existing 32ch in Classifieds to someone with a Boscam transmitter, or on Ebay)
    or
    swap out transmitter & PnP cable over to a TS353. Depending on how much you can sell the BP32ch for, this may be the cheaper solution... you can pick up a TS353 for about $32 and the PnP cable is only $11... you'll wind up under $50 to convert.
    then you have an ImmersionRC600 and PnP cable (I assume) to sell.