Signal strenght measures in dBm of Inspire 1, M600 Pro and Mavic Pro

[niki]

Recently I've got RF Explorer 6G combo and started measuring the radio emmissions strenght of whatever I found at home So here are some results for some of the drones I have. This could be helpful to someone as reference. I'm in Europe so all drones are set to CE emmision strenght and all measurements where done by literally touching the antennas of the RF Explorer to the RC's or the Aircraft antennas.

Inspire 1 Raw, latest firmware:
RC 2.4Ghz -33.0 dBm
RC 5.8Ghz -29.5 dBm
Aircraft - 2.4Ghz -27.0 dBm

M600Pro, latest firmware:
RC 2.4Ghz -28.0 dBm
RC 5.8Ghz -28.0 dBm
Aircraft - 2.4Ghz -6.0 dBm

Mavic Pro, fw v1.03:
RC 2.4Ghz -5.5 dBm
Aircraft - 2.4Ghz -12.5 dBm

From this data can be seen that Mavic Pro RC also the M600Pro Aircraft are having some badass strenght compared to the rest. As usual Inspire is the weakest one from all aspects (RC and Aircraft). It will be interesting if someone have such data on his own to compare.

Edit:
Removed the lines for inspire and m600 with 5.8Ghz for the aircraft which was accidentally typed in.

 

[Dave Pitman]

Were you able to measure the increased gain using your yagi?

 

[niki]

Were you able to measure the increased gain using your yagi?

Those Yagi adapters are not increasing the gain as any other signal reflector accessory, they are "focusing" the signal. For increased gain you need signal amplifier or to increase the gain of the transmitter itself.

 

[Dave Pitman]

Those Yagi adapters are not increasing the gain as any other signal reflector accessory, they are "focusing" the signal. For increased gain you need signal amplifier or to increase the gain of the transmitter itself.

What is the difference between increased "focus" and increased gain? If you "focus" more of the transmission energy into a tighter directional beam, aren't you increasing the "gain" in the beam while decreasing gain when outside the beam? And if so, that would be measurable with RF equipment.

Understanding Antenna Gain - Telewave.io

Antenna gain indicates how strong a signal an antenna can send or receive in a specified direction. Gain is calculated by comparing the measured power transmitted or received by the antenna in a specific direction to the power transmitted or received by a hypothetical ideal antenna in the same...

www.telewave.com

 

[niki]

What is the difference between increased "focus" and increased gain? If you "focus" more of the transmission energy into a tighter directional beam, aren't you increasing the "gain" in the beam while decreasing gain when outside the beam? And if so, that would be measurable with RF equipment.

Understanding Antenna Gain - Telewave.io

Antenna gain indicates how strong a signal an antenna can send or receive in a specified direction. Gain is calculated by comparing the measured power transmitted or received by the antenna in a specific direction to the power transmitted or received by a hypothetical ideal antenna in the same...

www.telewave.com

First you should make difference between dBm and dBi. The first is measuring decibels per milliwatt and the second is measuring decibels per isotropic. My mesurements as you can see are in dBm and are not related to the isotropic characteristics of the measured antenna.

 

[Brett8883]

Recently I've got RF Explorer 6G combo and started measuring the radio emmissions strenght of whatever I found at home So here are some results for some of the drones I have. This could be helpful to someone as reference. I'm in Europe so all drones are set to CE emmision strenght and all measurements where done by literally touching the antennas of the RF Explorer to the RC's or the Aircraft antennas.

Inspire 1 Raw, latest firmware:
RC 2.4Ghz -33.0 dBm
RC 5.8Ghz -29.5 dBm
Aircraft - 2.4Ghz -27.0 dBm
Aircraft - 5.8Ghz -43.0 dBm

M600Pro, latest firmware:
RC 2.4Ghz -28.0 dBm
RC 5.8Ghz -28.0 dBm
Aircraft - 2.4Ghz -6.0 dBm
Aircraft - 5.8Ghz -50.0 dBm

Mavic Pro, fw v1.03:
RC 2.4Ghz -5.5 dBm
Aircraft - 2.4Ghz -12.5 dBm

From this data can be seen that Mavic Pro RC also the M600Pro Aircraft are having some badass strenght compared to the rest. As usual Inspire is the weakest one from all aspects (RC and Aircraft). It will be interesting if someone have such data on his own to compare.

This is very interesting thanks!

I didn’t realize Inspire 1 had a 5.8 signal coming from the aircraft? I thought 5.8 was just from Slave RC to main RC?

For the uninitiated can you please explain why the levels are negative please? I thought a negative dbm was like extremely weak signal?

 

[niki]

I didn’t realize Inspire 1 had a 5.8 signal coming from the aircraft? I thought 5.8 was just from Slave RC to main RC?

Thanks for noting that! It's a mistake I probably did while making the post, the 5.8Ghz data typed for the inspire aircraft is actually from one of the other devices I measured at home and it looks I've mixed up the data accidentally.

For the uninitiated can you please explain why the levels are negative please? I thought a negative dbm was like extremely weak signal?

Yes it is very weak signal but that is because I'm not measuring with cable connected directly to the transmitter without using antennas, but trough the antennas the signal become attenuated. For example a relatively good wifi signal is rated to be -70dbm, at home my router is showing -40dBm when I touch the antennas. For the remote controlled "toys" we use it's much stronger so they can reach a few km range which a home router cant reach.

 

[Brett8883]

Thanks for noting that! It's a mistake I probably did while making the post, the 5.8Ghz data typed for the inspire aircraft is actually from one of the other devices I measured at home and it looks I've mixed up the data accidentally.


Yes it is very weak signal but that is because I'm not measuring with cable connected directly to the transmitter without using antennas, but trough the antennas the signal become attenuated. For example a relatively good wifi signal is rated to be -70dbm, at home my router is showing -40dBm when I touch the antennas. For the remote controlled "toys" we use it's much stronger so they can reach a few km range which a home router cant reach.

Got it thanks!

 

[niki]

2 years ago I have replaced all the motors after shooting day with very strong winds - more than 50km/h. The replacing procedure involved resoldering of the antennas inside the legs, all the soldering was done professionaly. We did some tests after and the radio connection at the time was great but trough the time we started facing some connection problems that gradually where becoming worse.
So after the RF measurements I did and looking at the resulted data which was kind of inconsistent between all the antennas I decided to resolder the antennas that are on the Inspire and guess what, I've got a huge improvement. After doing that we had a few shooting days where the connection was exceptional and nothing like it was trough the last year, there where not even a glitch on the master and slave controllers despite the huge crews that where around, previously it was happening at some locations to lose signal when the drone is at 100m from us. So it could be the solder tinol being degraded trough the time as it was pretty good right after the motor replacement. I guess it could be a common problem even for a stock soldered antennas having in mind the huge vibrations that the drone produces and the big time interval of use, our is flying intensively from 2016 up to date. So for the people who are facing some radio connection problems they may consider doing maintanence of the antennas even their cables and the connectors to the inspire's brain.

Here's a table with measurement data of before and after. I also did every antenna multiple times to be sure I 'm getting the maximum available dBm as there was still difference between every antenna but overal all of them became much much better.

 

[Brett8883]

2 years ago I have replaced all the motors after shooting day with very strong winds - more than 50km/h. The replacing procedure involved resoldering of the antennas inside the legs, all the soldering was done professionaly. We did some tests after and the radio connection at the time was great but trough the time we started facing some connection problems that gradually where becoming worse.
So after the RF measurements I did and looking at the resulted data which was kind of inconsistent between all the antennas I decided to resolder the antennas that are on the Inspire and guess what, I've got a huge improvement. After doing that we had a few shooting days where the connection was exceptional and nothing like it was trough the last year, there where not even a glitch on the master and slave controllers despite the huge crews that where around, previously it was happening at some locations to lose signal when the drone is at 100m from us. So it could be the solder tinol being degraded trough the time as it was pretty good right after the motor replacement. I guess it could be a common problem even for a stock soldered antennas having in mind the huge vibrations that the drone produces and the big time interval of use, our is flying intensively from 2016 up to date. So for the people who are facing some radio connection problems they may consider doing maintanence of the antennas even their cables and the connectors to the inspire's brain.

Here's a table with measurement data of before and after. I also did every antenna multiple times to be sure I 'm getting the maximum available dBm as there was still difference between every antenna but overal all of them became much much better.

View attachment 29478

Very interesting! Thanks!