Mavic Pro EU compliance and transmit power

[Kilrah]

Well I am in an EU location and can select the channel and channel width.

Not sure whether the graph shows what the aircraft or controller is reading.

 

[Ender]

Well I am in an EU location and can select the channel and channel width.

Not sure whether the graph shows what the aircraft or controller is reading.

I know, Kilrah
Its just that youare also around in other parts of the world and so i thought maybe you use that customization somewhere else...
Will check again, maybe its no CE but a German thing or maybe i simply missed it somehow

Ender

 

[Scuba]

Ok guys thanks for your replies....First I switched to my ipad mini because my phone was dead,then I changed to custom and tried 10mhz ..headed in same direction with same results so I tried another direction....this time I was able to go 7000ft and still had 3 bars sometimes 4 so I turned around...It looks like the bird is fine and I just have alot of interference here and the 2 other places i tried..I need to find new places lol

 

[4wd]

Nice calm day here in CE land so easily went to about 2km with no change to signal bars.
This was also possible with Phantom 3 but the Mavic is much faster, in fact it went 2km one way, back home and 2km the other way on one battery and still had 40% remaining at landing.

 

[flyNfrank]

Is there a way I can verify what tx power is it on (eu standards caps the power pretty low).

No.

Technically...that is a incorrect response. A Trifield Meter can determine output. The images below show testing of a Mavic R/C fitted with a WindSurfer Antenna Enhancer.

 

[chazzm]

According to the Mavic user manual page 56:

Transmitter Power ( EIRP ) FCC: ≤ 26 dBm; CE: ≤ 20 dBm

This translates into FCC ≤ 400 milliwatts transmitted power ; CE ≤ 100 milliwatts transmitted power.

Hope it helps.

I haven't really thought about that, but I'm a dummy when it comes to transmitting power,, I have replaced antenna before and all but the math is beyond me at this time lol, but how does a difference between 26 and 20,,,,,, 6 points equal 300 milliwatts? I'm not doubting you I'm just trying to unravel that in my brain,,,,


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[DarkEnergy]

I haven't really thought about that, but I'm a dummy when it comes to transmitting power,, I have replaced antenna before and all but the math is beyond me at this time lol, but how does a difference between 26 and 20,,,,,, 6 points equal 300 milliwatts? I'm not doubting you I'm just trying to unravel that in my brain,,,,

The decibel scale is logarithmic and therefore it describes a multiplicative change in power.
3 decibels corresponds to a x2 change in power, 6 decibels is a x4 change in power, 10 decibels is a change of a factor of 10, etc.
The change in Transmitter Power of 6 dBm between ( EIRP ) FCC: ≤ 26 dBm and CE: ≤ 20 dBm corresponds to a factor of 4 in Power, FCC ≤ 400 milliwatts and CE ≤ 100 milliwatts.
Hope it helps, if not look at "decibel' in Wikipedia.

 

[4wd]

It doesn't mean FCC range is 4x greater though, signal attenuates in surprising ways.
We used to get a lot of surprises using CB radio in the 1980s. with higher power often giving surprisingly little advantage.
The main influence on how far you can go and how solid the reception will be choosing a good start point - ideally somewhat elevated and no trees or buildings close by.
A single tree in just the wrong spot can have a dramatic affect and just moving a a little to the side will regain good signal. It might not even be directly inline, you still get a back-scattering effect which has a negative effect.
Trees in leaf are much worse than bare branches.

 

[DarkEnergy]

In ideal conditions illumination, or in this case power flux, drops as the square of the distance, thus increasing four times the power will allow at best to reach twice the distance.

 

[Timbooo]

Does the Mavic use the GPS location or origin of purchase for setting FCC/CE compliance?


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[halley]

In ideal conditions illumination, or in this case power flux, drops as the square of the distance, thus increasing four times the power will allow at best to reach twice the distance.

We used to get a lot of surprises using CB radio in the 1980s. with higher power often giving surprisingly little advantage.

DarkEnergy and 4wd are both correct. It's actually a good idea for folks to try for their amateur radio technician license (be a "ham"). It's like $50 bucks, and a short written test. The study materials for the test are very illuminating and help you understand a lot more about power vs range vs interference.

 

[bertie]

Finally got to doing a proper range test in a non-urban environment, and boy is the range fantastic!

This is the noise floor for the area, very clean.
View attachment 1049

Even at 5,000 meters out, there were still 4 bars on both control and HD link.
View attachment 1050

7km should not be an issue. Bloody impressed!

One thing I noticed is that the app advises to change to 10M link manually when high interference is detected.

Was this in the eu?


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[Ender]

Hi !
I reached 3km@100m Altitude in CE mode, flat terrain, virtually noise free and there was still some headroom...

I wont count the bars as many companies choose to display 4/5 bars up to the very last moment where the "bars" drop like a rock to keep up the illusion of good reception as long as possible. Maybe not DJI but as long as we do not know the SNR for each bar its not worth much.

Greetings,

Ender