FlySKy MOD Range Test

As soon as I received my devo8s yesterday, I added a flysky module from v929 radio to devo 8s.

V911 was successfully bound to devo8S!

However, it seems that a range is very short.

After bounding it at living room, if I go to a room, v911 lost a signal.

If there is only one wall between a radio and v911, the v911 lost a signal.

Is it normal?

Hi,
I have the same issue in my Devo 6 with the V911-Tx module.

I have testet with a transmitter module from the transmitter which came with the Xieda 9958. This module have no HF-Power amp. The transmitter range was with this module only a couple of cm.

With the Tx-module from the V911 Transmitter, I have a range from 2-3m.

So I don't know if I have done a mistake. But I think not.
What can I do?

EDIT:
I have tested the 2.0 and the 1.1.2 release.

I have it tested with the module outside the transmitter, the range is a little bit longer but far far away from 10m.
The battery voltage is also the same with different output powers. With the Devo module falls the battery voltage.

Ok I test the 1.1 release today evening.

I have probably one more V911 Tx-module. I can test it with this module after the christmas holidays.

Is it possible that there are exist different Tx-module?

Are there things that I can test? I Have a LA and a 250MHz scope.

This two points I have already checked.

Only the module of the transmitter from the Xieda 9958 has no PA.
My module from the V911 looks identical to the module from your pic.

Anything else? Is it possibly that the problem is my Devo 6 and not Devo 8?

I have checked it with the 1.1 release.
It is now not possible to bind again.

I will check if the Tx-module is damaged. So I will solder it into the old transmitter.
When I will get the new Tx-module I try it with this one.

Perhaps I have done a mistake in the bind process.
Can you describe how to bind with the flysky tx?

Today I carefully did the range test again as follows.
1) I turned on a radio (FW 2.0) and changed its output power to 150mW.
2) Then, turn it off
3) plug a battery of v911 in
4) turn on devo 8s.

I put a radio in room #1.
Then, went to another room #2 with v911.
Distance between two rooms is only around 5~6m, but doors of the rooms were closed.

Interestingly, signal was alive.
The result was different from yesterday

In weekend, I'll do range test in open space like PB, and will report it.

kille wrote: Perhaps I have done a mistake in the bind process.
Can you describe how to bind with the flysky tx?

In "Model Setup", 1) choose Flysky protocol.
2) Set TX power to 150mW
3) In my case, Fixed ID: NONE

1) plug a battery to v911.
2) Turn on a radio
3) after a few second, v911 is bound.

Probably, the reason for the short range in the first test is that I didn't maximize TX power.

I Think I have found the reason.

I have soldered the Tx-module into the old Transmitter. Suddenly it bound then it lost the signal.
It works sometimes when i touch the Tx-module and sometimes not.
On the Tx-module is a inductivity broken. I have seen a small crack under my microscope.

I have no idea which is the right value. I have desoldered the induktivity and instead of the induktivity a bridge.
It dont work.

I wait for the next Tx-module.

Thanks everybody for the help and of course spezial thanks to PhracturedBlue.

PhracturedBlue wrote: I did a range test on mine. Around 1000ft with the V911 Tx module inside the Tx. I am not aware of any reason why the range would be so short. In 2.0 we added the ability to change the transmit strength. I am not 100% sure that has been thoroughly tested. In 1.1 we used stock settings (which is what I did the range-test with) so if you don't get good range with the 1.1 release, I am at somewhat of a loss.

Today I did the range test in an open space.
The range was only around 100ft.
There was nothing between v911 and a radio.
I have no idea why the range is so short.
If soldering is not good, is there any power drop in tx module?
Another possibility is that here is a big city.
Maybe there was some interference.

PhracturedBlue wrote: Assuming it is the inductor attached to the antenna, it is probably 3.1nH. there is also a 4.7nH incductor that is between the output and ground.

This is based on the reference design, and notnecessarily the same as the V911 module uses

Thank you very much for this advice. I order next time a suitable inductivity.

harmony96 wrote: Today I did the range test in an open space.
The range was only around 100ft.
There was nothing between v911 and a radio.
I have no idea why the range is so short.
If soldering is not good, is there any power drop in tx module?
Another possibility is that here is a big city.
Maybe there was some interference.

I get my new Tx-module. Now I can bind to my v911.
I have the same issues with the short radio distance.
It could be that the problem is not the modded Devo. It could be that the problem is the v911!
I have a nother issue with the v911. I have made a video.
I try to explain (my english is very bad, please excuse):
When I move the sticks very fast, the servos begin to "stick" and then it lost the signal.
I have testet this again with my th9x and I have the same problem (not so big but it exists).

With my Xieda 9958 heli and my v929 I have no problems like this.

So it could be that the range test with the v911 is bad but only because the v911 is bad.

Sorry the video upload dont work.
You can find the video there:

Maybe one direction to expore is try another V911 heli and see if it acts the same as the one you are doing the tests with right now?

I have tested it with two different v911. It is the same.

With a bigger distance the problem is bigger.

kille wrote: It could be that the problem is not the modded Devo. It could be that the problem is the v911!

Today I did a test using v911, v929, and flysky receiver.
Interestingly, their ranges were different.
Maybe the reason for the short range in my previous test was that I did a test with the worst one.
The flysky receiver provided most long range.

I'll do a field test using v911, v929, and flysky receiver in weekend.

BTW, the transmitting power becomes 4 times, the range will theoretically become two times. Am I right?