Dave McDonald

My Feedback: (19)

Very interesting video!

To me it proves the FrSky receiver can be swamped with two transmitters placed very close to it.

But if the two other transmitters are moved a little farther away, I wonder if the same thing happens?

TimBle

Hmmm I wonder about that. A club mate and I tried that very test a couple of weekends back and the same problem did not surface. The Fr_Sky Rx worked just fine after a reboot with other Futaba 2.4 Ghz Tx within a metre.

Radimani

We tested this before taking off. Once saw this symptom, my friend immediately uninstalled the FrSky from his plane.
As to the distance between the receivers and the transmitters, we also tried this trial around 10 meters but we were able to duplicate the issue too.

Dave McDonald

My Feedback: (19)

Just so there is no confusion, you are saying that you ran a similar test to the one in the video, but all of the transmitters were 10 meters away from the FrSky receiver, and the FrSky still would not respond to it's transmitter. Is this correct?

I have attached a diagram showing the relative positions of the receiver and the three transmitters.

Radimani

Exactly!

Dave McDonald

My Feedback: (19)

Radimani,
Thank you for taking the time to run those tests on the FrSky receiver, and also for sharing your results!
It is greatly appreciated!

Roo Man

My Feedback: (1)

As I understand it these tests were for the Orange FASST receiver and not the Frysky 72MH conversion receivers. Any similar problems with the 72MH conversion?

Gary

TimBle

tried the test today. The receiver responded to the Tx it is bound too.

Dave McDonald

My Feedback: (19)

Did you try the "bunched up" test? Or the "10 Meter" test? Or both?

TimBle

bunched up test. It reboots and rebinds to the same Tx no problem so I'm not sure whether the video shows a bad Rx or if its a contrived video to dent FrSKy market impact.

Dave McDonald

My Feedback: (19)

That exact same thought crossed my mind too.

I'll reserve my final opinion until after running this test myself. The results will be posted here.

TimBle

Just ran the test again this time with the R606FS and the TFR-8 in the Seawind Ep and Tempo trainer respectively, with servo's connected. Both planes on the ground next to each other and the T6EX (radio the Rx are bound too) and my T8FG right next to each other.

On tx power down both Rx lose the connection obviously. On Tx power up it takes about 1.2sec for the TFR-8 to re-establish connection and about the same for the R606FS
Then tried it with R617FS and it rebinds almost on power up.
This is consistent the reasoning why Futaba discontinued the R606FS and essentially used the R617FS as the std Rx in their range.

I then moved the Tx further apart, 2m and tried again, no issue. then I moved the TX outside, one in the garage and the other on the other side of the yard so about 15m apart and still no issue. I could not gauge relink time of course but control surfaces moved after about the same time as when the Tx were right next to each other.

Now the question is, is loosing the connection between Tx and Rx a real issue with the FrSKY Rx system? In my experience no, its not if one follows the normal pre flight checklist related to radio link safety. Are your batteries charged? Do they deliver sufficient current?

I'm still working up the flight time on the TFR-8 so 12 flights is no measure of reliability. I'd have to observe the unit for about 6months and get at least 50 flight on it to be really confident in its performance.
I still trust genuine Futaba Rx more simply because of knowledge of the brand and their desire for quality.

Bare in mind that its probably quite simple to brew up a test to show the FrSKY in a bad light, especially if its hurting someones sales. Just suffiecient doubt is enough to dent trust.
Could be anyone with a vested interest. Always check the information for yourself.

Radimani

The set-up of all transmitter was "multi-ch" mode. I don't know how the result change if the mode is "7ch".

TimBle

straight away, I know its BS.

iforbes

My Feedback: (3)

It kind of seems like BS. I am interested if anyone else will be able to duplicate the issue....

Dave McDonald

My Feedback: (19)

Radimani,
Please don't be insulted, but I'm sure everyone wants to know the answer to this question.

Do you work for, or have a vested interest in a competitor of FrSky?

Radimani

I'm just one of modelers. One of purposes of my post is to let FrSky know this fact as I hope they can fix this phenomenon. Some of people in this thread might think that my post is uncomfortable but I did not use any particular means to shoot the video. If need be, I will try to re-shoot it on condition that the system away 10 meters apart. But I already returned the transmitters to my friend thus please allow me to have some time. Anyhow, I beleive that FrSky already started to check and fix it soon. When they fixed it I'll be happy to use it!

meanrc

My Feedback: (2)

I have tried this test using 3 different frsky receivers and did not get Radimani's results. All three preformed perfect. I will trust what I have.

Dave McDonald

My Feedback: (19)

Radimani, thank you for verifying you have nothing to gain by pointing out the problem you are having with your FrSky receiver. But other than your friend, no one else has been able to duplicate your results so far.

I think that 2.4 transmitters in Japan are limited to less power output than in USA. So now I'm left with more questions than answers.

Maybe the FrSky doesn't have a problem with higher power 2.4 transmitters?

Or maybe FrSky already fixed the problem?

Or maybe Radimani has an older model receiver?

Radimani

Dave,

I don't know anything about your questions since all I know is the test result. But I guess that the receiver I tested is realtively older version.
Anyhow, I tested again. I'm not sure how much the metal can can attenuate the RF signal but the condition for the receivers is much nicer than previous test.
The mode of interference transmitters is "multi" mode.

http://www.youtube.com/watch?v=crZoOYiGlF4

Dave McDonald

My Feedback: (19)

I had a chance to try Radimani's test today. The FrSky receiver was in a plane and was bound to a Futaba 12FG. A 12FG FASST and a 7C FASST were placed on either side of the receiver, and less than 1 foot away from the FrSky. Every time I turned the transmitter off and back on, the FrSky receiver immediately worked perfectly. I left the two interfering transmitters a foot away and walked out to different distances and repeated the test over and over. After walking over 200 feet away, I gave up trying to get the FrSky receiver to fail.

I'm still wondering if Japan's 10 milliwatt output limit has something to do with Radimani's results, since nobody outside of Japan has been able to duplicate Radimani's results.

Radimani

Dave,
Thank you very much for your testing. But as I specified that
"The mode of interference transmitters is "multi" mode. "
You conducted the test by 7C for one of interference transmitters. This won't create the issue.
All, including the desired transmitter, should be in "multi-mode".

http://www.youtube.com/watch?v=crZoOYiGlF4

Dave McDonald

My Feedback: (19)

You are correct. The 7C cannot operate in multimode, so my test was flawed. I had forgotten about the multimode requirement and simply grabbed a buddy's 7C because it was handy.

The next time I'm at the flying field I will repeat the test with all three transmitters in multimode, and see what happens.

TimBle

all should be in either Multi mode or all should be in 7Channel mode.
I cannot recreate the problem in either modes so I'm not going to spend any more time fretting about this. Currently they work and I'll continue flying them.

Radimani

We tried to check if only one disturbing transmitter is enough to cause the phenomenon.
Here comes the result. Please note that the undesired transmitter is in "Power Down Mode"
thus the RF power from the undesired is quite lower than the desired.

http://www.youtube.com/watch?v=XdP5Uxzy1XY