zukenj

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Re: OPlink Vehicle control looses it
« Reply #15 on: April 27, 2016, 07:51:32 pm »
I get disconnection at 10m indoor,and less the 2m in the field. I had try different channels, different Power settings, my next test will be, to have a USB connected to the FC, and a USB connected to the Ground controller, two different laptops, and monitor the dB rates in both.
FS-TH9X RC
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HK 30A ESC UBEC running BLHeli 14.4
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kennyevo

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Re: OPlink Vehicle control looses it
« Reply #16 on: April 27, 2016, 09:07:56 pm »
I get disconnection at 10m indoor,and less the 2m in the field. I had try different channels, different Power settings, my next test will be, to have a USB connected to the FC, and a USB connected to the Ground controller, two different laptops, and monitor the dB rates in both.

I'm curious about the result :)

f5soh

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Re: OPlink Vehicle control looses it
« Reply #17 on: April 27, 2016, 09:19:03 pm »
I'm curious about the result :)

That what i asked here: https://forum.librepilot.org/index.php?topic=1332.msg9734#msg9734
At least you can know the wrong device if the RF power is the issue.

From tests i did here i got around 100m where the link is completely lost, with minimal power (1.25mW)

zukenj

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Re: OPlink Vehicle control looses it
« Reply #18 on: April 27, 2016, 11:09:23 pm »
I will post a video with both laptops conected

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FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

finst

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Re: OPlink Vehicle control looses it
« Reply #19 on: April 28, 2016, 12:07:21 pm »
Did a quick test today:
Instead of moving the revo around, I  took my oplink for a walk after I started logging the revo. The log shows a signal strength of around -70db with a distance of about 50 meters between revo and oplink. Both devices connected, running at ppm only and at 100% power. The antenna used with the oplink is a sh77 diamond (or whatever it's called), on the revo side I use the stock one. That said, the indicator shows about -20db with both devices literally next to each other.
But since this was just a quick test, the leads of the antenna just hang around and were not pointed in any certain direction or fixed in a right angled position. Is this normal or should I look into my setup?

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zukenj

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Re: OPlink Vehicle control looses it
« Reply #20 on: April 28, 2016, 04:48:08 pm »
I'm curious about the result :)

That what i asked here: https://forum.librepilot.org/index.php?topic=1332.msg9734#msg9734
At least you can know the wrong device if the RF power is the issue.

From tests i did here i got around 100m where the link is completely lost, with minimal power (1.25mW)

Your post gave me the idea, on using 2 laptops to monitor the dB. I don't have the result yet, because it took me 2 and 1/2 hours to compile next in the second laptop, so I end up at 1:30 AM, and went to bed.
FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

zukenj

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Re: OPlink Vehicle control looses it
« Reply #21 on: April 29, 2016, 05:46:20 am »
Here is the video with the OPLink issue.

FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

f5soh

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Re: OPlink Vehicle control looses it
« Reply #22 on: April 29, 2016, 07:29:56 am »
Looks like your Oplink Mini do not transmit as expected.
Be sure all antenna side is ok, open the case and inspect solder joins.

zukenj

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Re: OPlink Vehicle control looses it
« Reply #23 on: April 29, 2016, 03:43:38 pm »
Thanks f5soh (L).

I will do that, tonight and post back.

FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

zukenj

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Re: OPlink Vehicle control looses it
« Reply #24 on: May 04, 2016, 04:27:46 am »
I don't see ane solder problem. Please check if you see any suspicious one.
FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

f5soh

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Re: OPlink Vehicle control looses it
« Reply #25 on: May 04, 2016, 07:21:37 am »
There a missing coil.
Usually this component is used to power a RF stage, make sense if no range.

Edit: Look like this coil is used for the small "G4C" component, the Tx/Rx antenna switch.
http://datasheet.octopart.com/UPG2179TB-E4-A-NEC-datasheet-26379.pdf

« Last Edit: May 04, 2016, 07:30:54 am by f5soh »

zukenj

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Re: OPlink Vehicle control looses it
« Reply #26 on: May 04, 2016, 10:01:14 pm »
I see.  :'(

Picture from AliExpress Coil.png


Picture from banggood.com Coil_2.png
FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS

hwh

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Re: OPlink Vehicle control looses it
« Reply #27 on: May 04, 2016, 10:14:45 pm »
Complain to the seller, maybe they'll replace it.

If not the entire RFM22b module runs about $6 US on eBay if you can solder.

Brian

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Re: OPlink Vehicle control looses it
« Reply #28 on: May 04, 2016, 10:41:22 pm »
It's not easy to desolder those modules.  You really have to heat both sides at once, which means a very large nozzle on a hot air gun, which means that many more parts might come undone as well.  Carefully working it with a solder sucker and/or wick might work, but I'm not sure it's worth it.

zukenj

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Re: OPlink Vehicle control looses it
« Reply #29 on: May 05, 2016, 03:21:24 am »
Hwh,

Do you have a link just in case?


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FS-TH9X RC
F450 Clone
Revolution FC
EMAX 2213 935 KV
HK 30A ESC UBEC running BLHeli 14.4
10x4.5 Propellers
DJI Naza clone Ublox M8N GPS