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Thread: Poor Range with Crossfire?

  1. #41
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    So I think (and I hope) I managed to figure out the issues with my system. Here's an annotated side view of my quad:



    In green is the antenna wire going up my PTFE tube, blue is the ground part coming back down. Now the end of the ground part always used to be bent like the yellow bit indicates (plus a bit inwards the quad, hard to show in 2D). This always resulted in my Taranis complaining about low or critical RSSI (with the standard thresholds) like there's no tomorrow. Even today. Then eventually for some unrelated reason, I bent it like the purple part indicates, my RSSI when I'm about to take off went from ~65 to ~73 on the OSD scale (whatever moon units that represents, but it seems significant), the Taranis stopped complaining about RSSI, and I didn't notice any more random short bouts of control loss.

    My suspicion is that it picked up RF crap from the camera, that interfered with the receiver. The electrics themselves are relatively clean, because there's capacitance and filtering all over the place (altho I still want an oscilloscope eventually to tune this). And it used to happened randomly at hover, not just at load changes that cause lots of EMI.

    Knocking on wood that this drama is over.


    (Also, why the hell is this site still so slow after days?)

  2. #42
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    Quote Originally Posted by Glowtape View Post
    Knocking on wood that this drama is over......
    FWIW - I have two new builds using the micro and I shoved both the black and the silver antenna parts up the drinking straw - has been working perfectly so far. One of the builds even has the VTX antenna 25mm away.

    http://fpvlab.com/forums/showthread....l=1#post832048

  3. #43
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    I suppose it might work on close range, but I think folding up the ground plane part next to the active part is discouraged, because the ground part essentially receives the complementary version of the signal of the active part and things may cancel out. The reason this still works at all are probably differences in gain on both parts.

  4. #44
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    Thats the ambiguous part, I do not believe the black wire is meant to be a ground plane. I *think* it is more of a balun that acts to stop the RF from feeding back into the transmitter. As soon as these cyclonic winds here in North Texas die down to something reasonable I'll do a long distance run and see what happens.

    If the inventor of that antenna would chime in here that would be great. Numerous moon units would be awarded.

  5. #45
    Quote Originally Posted by Glowtape View Post
    So I think (and I hope) I managed to figure out the issues with my system.
    I'm glad you found something. Keep us informed.

    While testing I hit a failsafe, broke the antenna near the connector, can't replace the antenna without fine soldering, in a angry I trash it and bought the big diversity receiver... I'm done with the micro, it works fine for some and works poorer than a cheap frsky for other, nobody knowns really what to do, the range is aleatory and I hate aleatory issues.

  6. #46
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    Yeah, the jump in RSSI was surprising, and that happened before the motors were spinning, so the camera was really the only culprit here at this point.

  7. #47
    Quote Originally Posted by Glowtape View Post
    So I think (and I hope) I managed to figure out the issues with my system. Here's an annotated side view of my quad:



    In green is the antenna wire going up my PTFE tube, blue is the ground part coming back down. Now the end of the ground part always used to be bent like the yellow bit indicates (plus a bit inwards the quad, hard to show in 2D). This always resulted in my Taranis complaining about low or critical RSSI (with the standard thresholds) like there's no tomorrow. Even today. Then eventually for some unrelated reason, I bent it like the purple part indicates, my RSSI when I'm about to take off went from ~65 to ~73 on the OSD scale (whatever moon units that represents, but it seems significant), the Taranis stopped complaining about RSSI, and I didn't notice any more random short bouts of control loss.

    My suspicion is that it picked up RF crap from the camera, that interfered with the receiver. The electrics themselves are relatively clean, because there's capacitance and filtering all over the place (altho I still want an oscilloscope eventually to tune this). And it used to happened randomly at hover, not just at load changes that cause lots of EMI.

    Knocking on wood that this drama is over.


    (Also, why the hell is this site still so slow after days?)
    Tried this and dropouts are even worse.

    Also, what about "Immune to on-board noise" used in all the TBS marketing.

    All three of my receivers on three seperate builds each using a different antenna mounting. Something is clearly wrong with my hardware.

    I'm getting better performance on my non full range frsky xm than running crossfire at 500mw but then I hear about a person in my same city getting very far on a fixed wing with just 10mw. I've had the Crossfire since before Christmas and I now only run it on my warm up quad at 500mw and stay within 50 to 100m and still have dropouts. I have ZERO confidence in this gear.

    Perna, how can I go about getting my gear replaced? I've done ground tests showing you ample data. My RSSI will jump around by 20db with the quad sitting 100m away. I know you guys are busy but I've had my Crossfire over half a year and I'm still not up and flying with it. Can I please get some help here?

  8. #48
    Quote Originally Posted by LCurole View Post
    Tried this and dropouts are even worse.

    Also, what about "Immune to on-board noise" used in all the TBS marketing.

    All three of my receivers on three seperate builds each using a different antenna mounting. Something is clearly wrong with my hardware.

    I'm getting better performance on my non full range frsky xm than running crossfire at 500mw but then I hear about a person in my same city getting very far on a fixed wing with just 10mw. I've had the Crossfire since before Christmas and I now only run it on my warm up quad at 500mw and stay within 50 to 100m and still have dropouts. I have ZERO confidence in this gear.

    Perna, how can I go about getting my gear replaced? I've done ground tests showing you ample data. My RSSI will jump around by 20db with the quad sitting 100m away. I know you guys are busy but I've had my Crossfire over half a year and I'm still not up and flying with it. Can I please get some help here?
    Do you have a friend close by who uses crossfire too? If not I can send you a new TX and you can compare it against your TX? Please open a ticket and send me the ticket number in this case.

    Btw there is a new article:
    http://team-blacksheep.freshdesk.com...les/4000101963

  9. #49
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    This one is interesting:



    Kind of throws a spanner into my current setup with the PTFE tube. Because as per image posted on the top of this page, I evidently have the wire running parallel and right next to the ground part of the antenna. I guess this explains a lot of my issues. The wire part picking up an inverted version of the signal the ground part gets, cancelling each other out.

    I guess I have to try the V-shape, and consider changes to by upcoming frame to mount it straight (holes through both top and bottom plates, PITA to take off though).

  10. #50
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    Quote Originally Posted by Glowtape View Post
    This one is interesting.
    Where did that picture come from? The wire on the left is actually a balun that prevents feedback and not an antenna. Unless Alex or TBS wants to chime in and correct me, pretty sure its not going to mess with your reception. I have it shoved up the PTFE / Drink straw on two copters, QAV-X and a TBS G2 and can easily get 300 meters / 1000 feet with no problems. Do you have a scope where you could look at your supply thats feeding the RX? Maybe there is some noise on there. With the powercube I discovered (the hard way) that if you are going to be drawing much current on from the powecube PDB you have to remove the jumper resistor and replace it with a solder bridge. With the resistor in place I was seeing ~4v on the 5v rail and it was shaky.

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