Any experience with dual band boosters and dual band antennas on I2?

[DrMrdalj]

I am looking for potential mod of I2 stock controller or Candence controller, to gain stronger emission and reception, in order to have reliable control and video signal in urban areas and when flying over water... So, while studying all info which I could gather, I got a bit confused on I2 antenna signal path and relevance of dual band boosters.

By looking on I2 controller internals, it seems to me that stick antennas are 2.4GHz only, while there are two small patch antennas inside the controller which cover 5.8GHz band. Same construction is implemented in Candence as well, where "free of charge" external patch antenna covers only 2.4GHz band. Am I right in this assumption, or stick antennas are actually dual band 2.4/5.8? If that is the case what is the purpose of small patch antennas inside controller?

Having in mind my assumption that stick antennas are only 2.4GHz, I can not understand how do "dual band range extenders" promise higher emission and reception signal gain on both bands. I was looking at 4hawks patch antennas, as well as on Sunhans dual band signal booster, both listed on MAXXUAV as I2 compatible

Raptor XR
Sunhans Dual Band 2.4/5.8 GHz amplifier amp booster

If stick antennas are actually dual band, then it seems very straightforward to connect any booster or patch antenna on Candence controller, as its antenna connectors are MCX type. In that way you could have several antena systems easily exchanged depending on the circumastances... Am I right or I miss some understanding?

Do you have any info on actual 2.4 and 5.8 band signal path, or any experience with modification of stock antenna system in I2 controllers?

 

[DrMrdalj]

Here are some details which I learned in communication with members of certain Facebook group:

James Crutchfield: The stock antennas on the Inspire 2 rc are dual band. The same goes for the Cendence. The two patch antennas are 5.8 antennas for dual camera ops.

So, it seems that the same two whip/stick antennas transmit and receive aircraft signal in both 2.4 and 5.8GHz modes, while internally glued patch antennas work separately for master-slave communication between controllers.

 

[Jason Boucher]

Here are some details which I learned in communication with members of certain Facebook group:

James Crutchfield: The stock antennas on the Inspire 2 rc are dual band. The same goes for the Cendence. The two patch antennas are 5.8 antennas for dual camera ops.

So, it seems that the same two whip/stick antennas transmit and receive aircraft signal in both 2.4 and 5.8GHz modes, while internally glued patch antennas work separately for master-slave communication between controllers.

I would agree with this as well because if you read the DJI documentation it shows different ways of positioning the Stick antennas depending on if you are using 3.4 or 5.8

 

[DrMrdalj]

I would agree with this as well because if you read the DJI documentation it shows different ways of positioning the Stick antennas depending on if you are using 3.4 or 5.8

With due recpect, it would not be the first time that DJI publishes misleading semi-correct info. Please note that stick antennas are linearly polarized omnidirectional whips, therefore they radiate strongest signal in direction perpendicular to antenna while weakest signal is on antenna axis, and that goes for all frequencies.

Therefore positioning of antennas, regardless of the frequency, strongly depends on a way you hold RC controller. As you can see in the manual on the right part of the illustration - when controller is held strongly angled over horizontal then antennas are moves in vertical position to provide better range...

The same illustration kept me under impression that small patch antennas that are glued inside controller work for aircraft communication in 5.8GHz band, as DJI suggest that whip antennas get moved out of the signal way (buy putting them completely up to the controller back)...

 

[n5101]

Just a disclosure: "any further increase in transmit power on Inspire 2 or use of licensed frequency would require FCC authorization"

There is an easier way to attain the result desired.
Remove transmit power limitation & to use unsaturated (less interference) 2.6GHz band for rotorcraft control.
In the US transmission power is software limited to 500mW.
But controllers chipset allows output up to 1.5W, the rotorcraft Tx power (if remember correctly) 950mW.
This can be achieved by modifying DGI Go application internal settings (both iOS & Android).
My test had shown range & substantial signal stability increase without any adverse effects.

 

[DrMrdalj]

Just a disclosure: "any further increase in transmit power on Inspire 2 or use of licensed frequency would require FCC authorization"

There is an easier way to attain the result desired.
Remove transmit power limitation & to use unsaturated (less interference) 2.6GHz band for rotorcraft control.
In the US transmission power is software limited to 500mW.
But controllers chipset allows output up to 1.5W, the rotorcraft Tx power (if remember correctly) 950mW.
This can be achieved by modifying DGI Go application internal settings (both iOS & Android).
My test had shown range & substantial signal stability increase without any adverse effects.

That is really tempting solution, but it is constantly evolving effort, challengeed with every new app version and new firmwares coming, Nevertheless, I am really interested in that topic, and made some test myself with earlier GO App 3 and Inspire 1, with mixed success... When switched to I2 I was conservative not to mess up something and void warranty on still unproven product, and after a while I was informed that GO App 4 settings joined with the recent I2 firmware got locked down... Or they are still editable somehow?

Did you have success in modding last Go App 4.1.18 and I2 fw 01.01.0010, remote fw V01.01.0001?
Do you have any additional info, resource or recommendations regarding that mod?

 

[n5101]

it is not possible to post links to "hacks" on this forum. (I guess sponsors...) But there is website dedicated to that.

Personally I modified original firmware (there is an application for that, no special knowledge required) removing all no flight limitations, landing on battery low ect.
and did differential firmware upgrade to latest (updating only parts of firmware that were seemed necessary to me) on I2,
As of now the way applications designed for iOS and Android (that's where the Tx & channel settings are) are easily modified.
The only catch is that after you modified iOS application you have to sign it with Apple Developer Certificate ($100 a year membership) to install on iPad, no such problem with Android.

Warranty is not a concern because you can always flash unmodified version of firmware using above mentioned application.
Modification to DJI Go are not traceable and not recorded anywhere.

 

[DrMrdalj]

it is not possible to post links to "hacks" on this forum. (I guess sponsors...) But there is website dedicated to that.

Personally I modified original firmware (there is an application for that, no special knowledge required) removing all no flight limitations, landing on battery low ect.
and did differential firmware upgrade to latest (updating only parts of firmware that were seemed necessary to me) on I2,
As of now the way applications designed for iOS and Android (that's where the Tx & channel settings are) are easily modified.
The only catch is that after you modified iOS application you have to sign it with Apple Developer Certificate ($100 a year membership) to install on iPad, no such problem with Android.

Warranty is not a concern because you can always flash unmodified version of firmware using above mentioned application. And modification to DJI Go are not traceable and recorded anywhere.

Thanks a lot for the info, it is nice to know key steps that worked well for you. I will give it a try for sure.

 

[n5101]

I have only one advice, since there are a lot of parameters that could be changed, be conservative, do only what is necessary for your mission.
Use common sense. For example if you decide to increase maximum speed, also increase the obstacle avoidance distance, because default settings will not slow down I2 in time and you can crash.

 

[DrMrdalj]

I have only one advice, since there are a lot of parameters that could be changed, be conservative, do only what is necessary for your mission.
Use common sense. For example if you decide to increase maximum speed, also increase the obstacle avoidance distance, because default settings will not slow down I2 in time and you can crash.

Thanks for the reminder. As silly as it could sound, I still prefer to find myself as "pilot in FULL command", flying Atti, without sensors interference, without obstacle avoidance and complex RTH modes... Only alarms on hardware malfunctions are welcome

 

[Jason Boucher]

With due recpect, it would not be the first time that DJI publishes misleading semi-correct info. Please note that stick antennas are linearly polarized omnidirectional whips, therefore they radiate strongest signal in direction perpendicular to antenna while weakest signal is on antenna axis, and that goes for all frequencies.

Therefore positioning of antennas, regardless of the frequency, strongly depends on a way you hold RC controller. As you can see in the manual on the right part of the illustration - when controller is held strongly angled over horizontal then antennas are moves in vertical position to provide better range...

The same illustration kept me under impression that small patch antennas that are glued inside controller work for aircraft communication in 5.8GHz band, as DJI suggest that whip antennas get moved out of the signal way (buy putting them completely up to the controller back)...

I did some testing today using the Cendence remote with Patch Antenna.. I can fully confirm that the Patch Antenna is for sure 2.5 AND 5.8 GHZ.. I flew out to about 6,000 feet with 5.8 Ghz frequency selected and the Patch antenna connected. I then proceeded to disconnect the patch antenna.. Bang signal lost... Proving that the Patch Antenna does provide the 5.8 GHZ signal. Tried the same thing on 2.4 Ghz and received the same results.

As most people have said, the smaller antenna's inside the controller are strictly for master / slave communications, and the Patch antenna does do both 2.4 Ghz and 5.8

 

[DrMrdalj]

I did some testing today using the Cendence remote with Patch Antenna.. I can fully confirm that the Patch Antenna is for sure 2.5 AND 5.8 GHZ.. I flew out to about 6,000 feet with 5.8 Ghz frequency selected and the Patch antenna connected. I then proceeded to disconnect the patch antenna.. Bang signal lost... Proving that the Patch Antenna does provide the 5.8 GHZ signal. Tried the same thing on 2.4 Ghz and received the same results.

As most people have said, the smaller antenna's inside the controller are strictly for master / slave communications, and the Patch antenna does do both 2.4 Ghz and 5.8

Thank you! That are great news!
Some of the previuos reviews that I found on Youtube, as well as some on this forum, claimed that DJI Patch antenna bundled with an Candence, works solely on 2.4GHz band. Some of them ware unsatisfied of its performance... It is great to hear that they ware wrong.

Where did you fly for testing - is it possible that there are some georeferenced limitations on bands and transmitt power (forced by app thru CAN port of the antenna)?
Have you noticed any boost in range, comparing ti stock whipe antennas?

 

[Neugene]

As a newbie I'm unfamiliar with the site n5101 referred to that is dedicated to software/firmware hacks. I would very much appreciate it if someone would send me pm or a conversation message containing a link to the site.

Thanks,
Chris

 

[Top_gun_inspire1]

I just received my 4hawk xr will report back once I have it install.

I2 pilot looking for better transmission signal and better range.

 

[Raphael Dahan]

it is not possible to post links to "hacks" on this forum. (I guess sponsors...) But there is website dedicated to that.

Personally I modified original firmware (there is an application for that, no special knowledge required) removing all no flight limitations, landing on battery low ect.
and did differential firmware upgrade to latest (updating only parts of firmware that were seemed necessary to me) on I2,
As of now the way applications designed for iOS and Android (that's where the Tx & channel settings are) are easily modified.
The only catch is that after you modified iOS application you have to sign it with Apple Developer Certificate ($100 a year membership) to install on iPad, no such problem with Android.

Warranty is not a concern because you can always flash unmodified version of firmware using above mentioned application.
Modification to DJI Go are not traceable and not recorded anywhere.

Hi n5101, can you post please the all procedure or the workflow for the mod you made on the GO 4 for iOS sys. because i am also looking for best image and range transmission.
thanks in advance

 

[Viper62382]

Would love to know the site as well

 

[Joseph DeSalvo]

I just received my 4hawk xr will report back once I have it install.

I2 pilot looking for better transmission signal and better range.

Did you find that the 4hawk XR improves your signal? Did it work?

 

[The Editor]

Did you find that the 4hawk XR improves your signal? Did it work?

You realise this thread is over 2 years old and the member hasn't visited this site since March of last year?
I would suggest PM direct which will automatically send them an email.

 

[InspireMax]

Did you find that the 4hawk XR improves your signal? Did it work?

I got it, modified the RC with pigtails, I'm really happy with the upgrade. I had a maximum distance of 4.4 Km before, now, 6.7 Km in full safety, and I could fly some more meters before hitting RTH.
Very happy!!!
P.S. Antenna only, no amps, and I always select 2.4 GHZ for transmission

 

[The Editor]

I had a maximum distance of 4.4 Km before, now, 6.7 Km in full safety....

Oxymoron?......