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Old Jun 13, 2014, 06:24 AM
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Good luck! It certainly worked for me, for peace of mind I used to have the Taranis call out the RSSI every 5 seconds when climbing ... I have switched this off now
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Old Jun 15, 2014, 04:19 PM
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Quote:
Originally Posted by Bill Glover View Post
Good luck! It certainly worked for me, for peace of mind I used to have the Taranis call out the RSSI every 5 seconds when climbing ... I have switched this off now
Yes, this is the way to go. I have no FPV yet mounted so I tested the setup and it really works. No RSSI warnings at all, ( set to 60).

Look at this video, I surely learnt something today:
X8R PCB antenna test flight (1 min 19 sec)


I flew some 480 m away and lost the quad in the sky. The quad is relly small at that distance ;-)

Thank DJI for IOC-mode and Course Lock, it really saved my day.
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Old Jul 22, 2014, 11:59 AM
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This from the FrSky forum (from a FrSky rep): "whatever the "v", "L" or 90 degree, it is not a critical figure, but the most important thing is to keep the antennas away from each other to ensure the two antennas oriented on different directions to obtain the best results of the diversity function."
Now my take on that is that I want the antennas separated as far as possible and at an angle to each other.

Can anyone offer or speculate why FrSky made the leads of the PCB antennas so short?
I can buy non-PCB antennas up to 600mm on HobbyKing, but there aren't even replacements for the existing PCB antennas.

Has anyone tried the non-PCB antennas? A set comes with the X6R receiver. I wonder if having the PCB closer to other sources of RF radiation works better than non-PCB further away?

Also, are BOTH antennas receiving and transmitting? Or are they split-function, in which case two different antennas might be better? Their placement advice would indicate they are both doing both jobs.

I find the short leads dictate where I put my receiver which either dictates a long bundle of servo leads (my controller doesn't do SBUS) or it dictates where I put the controller too. But the controller position is dictated by the ridiculously short GPS leads! What is it with these manufacturers and WIRE!?

So the GPS has to be up high, and the receiver down low, but don't run anything past your ESC leads. Hey, no problem.
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Old Aug 13, 2014, 06:12 PM
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What is the purpose of the Frsky receiver for having 2 antennas?
I ask, because after a crash, one of my antenna came off, but the other is fine. The receiver is working fine too, but I would like to retire that receiver into a LOS park flyer only (just to be safe).
Anyway, so what is it for?
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Old Aug 13, 2014, 06:15 PM
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Quote:
Originally Posted by AlouetteII View Post
What is the purpose of the Frsky receiver for having 2 antennas?
I ask, because after a crash, one of my antenna came off, but the other is fine. The receiver is working fine too, but I would like to retire that receiver into a LOS park flyer only (just to be safe).
Anyway, so what is it for?
It's a diversity system. The Rx uses the strongest signal from the two antennas and switches as necessary. Your receiver will work, but you will be losing range and take the risk of losing control altogether.

The antennas on the newer models are easily replaceable. And the if you can solder, the older models are fixable as well.
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Old Aug 13, 2014, 06:42 PM
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Originally Posted by punkindrublik View Post
It's a diversity system. The Rx uses the strongest signal from the two antennas and switches as necessary. Your receiver will work, but you will be losing range and take the risk of losing control altogether.

The antennas on the newer models are easily replaceable. And the if you can solder, the older models are fixable as well.
Great news, I will try to solder it back. Thanks
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Old Jan 08, 2015, 11:24 AM
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I might have a biased opinion, but I'm a bit fond of this mount.
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Old Feb 19, 2015, 09:54 AM
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For a quadcopter it's especially important to place the antennas under the prop / body plane (at least if you intend to fly it above yourself... ;-) )

I have a setup similar to Bill Glovers, but with one antenna pointing down.

Best distance so far: 1.69 km (1,05 miles); did not loose radio signal, but FPV signal was below my comfort zone.
So I think if you fly in an area with low radio polution, the FrSky claim of >2km range is valid.
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Old Feb 19, 2015, 02:33 PM
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If you have distance and RSSI you can work out the theoretical range of your setup, knowing that RSSI drops by 6 each time you double the range. Loss of control occurs at around 38 - the default 'critical' alarm is at 42, so has a big safety margin built in.

From one of my log files I was hovering steady at 186 metres altitude for several minutes. The average RSSI during that period was 62.09. So doubling the range 3 times (to 1.5 km) would give an RSSI of 62 - 18 = 44 ... a very safe figure. Doubling again to 3 km would give 38, which is the 'loss of control' point. For quite a lot of the time my RSSI was at 70 or higher, which would equate to over 6 km range with everything well aligned. BoltRC have flown to 3.1 km (still with stock Taranis and X8R using stock PCB antennas).

So in practice 2-2.5 km should be fine with good antenna placement, and if you have a setup that automatically goes into RTH on signal loss you can push further in relative safety.

I just fly LOS so 200 metres or so is about as far as I go anyway!
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Old Feb 20, 2015, 05:26 AM
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Yes, my RSSI at the furthest point was around 50 so I could have gone further.
However, with local WLANs interferring (I assume) I had RSSI drops down to 45 less than 1km out - so I do those long distance flights only with RTH enabled.
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Old Feb 20, 2015, 06:28 AM
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My RSSI varied quite a lot on that flight while hovering at a fixed height more or less overhead. I assume this was down to change in orientation of the antennas as I yawed (taking pictures). But if you are flying away on a fixed course WLAN is certainly a possible culprit - you would expect a similar drop at the same range on the way back though.

Would be interesting to graph RSSI against time for your flight ... just a couple of clicks in the Companion (assuming you were logging the data).
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Old Feb 20, 2015, 06:37 AM
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Quote:
Originally Posted by Bill Glover View Post
My RSSI varied quite a lot on that flight while hovering at a fixed height more or less overhead. I assume this was down to change in orientation of the antennas as I yawed (taking pictures). But if you are flying away on a fixed course WLAN is certainly a possible culprit - you would expect a similar drop at the same range on the way back though.

Would be interesting to graph RSSI against time for your flight ... just a couple of clicks in the Companion (assuming you were logging the data).
WLAN and cordless phones (not mobiles/ cell phones, which don't use 2.4) are quite low powered and dont have much range, so I doubt you would get interference from them, but there are some radio beacons that also transmit on 2.4 in a narrow beam, which is why there may be an area of a flying site that gives problems.

Tom
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Old Feb 20, 2015, 07:10 AM
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I would guess you can buy high-powered (but illegal) WLAN repeaters though? Plenty of r/c fliers don't seem to worry about using video transmitters that are 20+ times the legal power output!
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Old Feb 20, 2015, 07:44 AM
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I would guess you can buy high-powered (but illegal) WLAN repeaters though? Plenty of r/c fliers don't seem to worry about using video transmitters that are 20+ times the legal power output!
True, but I don't think there is as much need for very long range with WIFI. It might even leave you vunerable to cyber criminals.

Tom
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Old Mar 31, 2015, 12:34 AM
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When the TX rubber stick is bent in the straight up position, like in the old days, we often vary the orientation up to 90 degrees while flying, as we move the transmitter. This could temporarily move it from vertical to horizontal polarization. In the horizontal position (bent to the right) it would not change as we tilt the transmitter front to back. This makes it a better choice to avoid temporary glitches as it is impossible to point it at the model while you are facing it. Turning to face your model comes naturally when flying LOS, but not FPV..

The same is true of the RX orientation. If we put both wires in the vertical position. As we are flying away it could vary by 45 degrees or more (multirotor). This is the most critical time to lose a signal without RTH. Because it would just keep on going. It may be the exact worst choice for a large forward pitch as the antenna would then be pointed at the controller.

Instead I suggest at least one wire be pointed horizontally to the side, not forward or backwards. This would always match the transmitter when going away or coming straight back.

In theory, the best choice for the other RX wire depends on if you most often go further while directly above or at the horizon turning to a perpendicular path. A vertical wire is useless when you are directly above. Perhaps the 2nd wire orientation is not critical, as long as it's different from the 1st?

The distance between the 2 wires on the RX is not important, unless you are trying to avoid other interference from a VTx that desensitizes the RX on the plane.

I have managed to modify the TX so I can use the L9R and a telemetry RX at the same time without interference. Even adjacent. Giving me a 5 mile range, and data at the same time out to about 2 miles. I have overcome some problems if you are interested.
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