Hi Guys
I was wondering if someone has made an attempt to place 2 antennas, 1 for 2.4ghz WIFI and 1 for 5.8GHZ WIFI, over the top cover (in the middle) of the aircraft ?

IMO , range can be expanded a LOT , using this mod (now it is in "Alpha" stage) thats why I am asking these questions to you.

My idea is to drill 2 holes, on the top cover, far from the propellers radius range. It will be in the center of the top side of the spark , and then, add 2 omnidirectional antennas (just like a router) 1 for 2.4 and 1 for 5.8 , and connect both antenas to the "main board" factory placed Ufl Connectors.

It will increase the range a lot , since external antennas wil have a great gain over internal antenas.

whats do you think about this Idea ?

comments , reccomendations, experiences will be welcomed

Thanks in advance

When I moved the antennae on a hubsan, it got worse

I still think about antennas mounted on/@ the rear or front legs.
The Air has now antennas at the front legs.
DJI didn't do that just  for fun.

Anyone have a picture of Spark internal antennas ? (mounted on the arms) Just to analyze performance, gain and so forth.

Thanks !

With  simple dipole antennae, placing it vertically is best except when the craft is above you. Then it wants to be horizontal.
In the rc aircraft world most receivers have had two antennae at 90 deg to each other for ages.
So mavic can do this because of its legs. Whether there's room in spark I don't know. DJI will definately know, but antennae design is very sophisticated.

ANAC PILOT Posted at 2018-1-29 08:34
Anyone have a picture of Spark internal antennas ? (mounted on the arms) Just to analyze performance, gain and so forth.

Thanks !

Left and right in front.

DaMa Posted at 2018-1-29 09:02
Left and right in front.

Thanks for the picture !!!! It seems that internal antennas are NOT INSIDE the ARMS, just close to the inside wall of the frame, Am I right ?

That´s what I see on the picture, please correct me If I am wrong.

ANAC PILOT Posted at 2018-1-29 09:06
Thanks for the picture !!!! It seems that internal antennas are NOT INSIDE the ARMS, just close to the inside wall of the frame, Am I right ?

That´s what I see on the picture, please correct me If I am wrong.

Yes, it looks like this. They are glued on and to get it in one piece down would be difficult – I think...

Not easy but it works... you have to be wary carefully.

Sorry for My Draw , I know I am Awful drawing, but is just a concept...

Whats do you think ? Without removing the original antennas, just adding 2 new external antennas (those like the routers have )

Fascinating.
My crude observations have suggested to me that reception/transmission varies noticeably with craft's orientation.
More noticeable when I was trying the rc antennae's  parabolic reflectors.

ANAC PILOT Posted at 2018-1-29 09:27
[view_image]

Sorry for My Draw , I know I am Awful drawing, but is just a concept...

Maybe. I found another solution for myself - Mavic Pro. The Spark is only for short distance ... and full speed in S-Mode until he glows...

Don't want to be a party pooper, but when I was gainfully employed in the electronics' industry it was absolitely prohibited to handle sensitive equipment such as the spark contains without static discharge protection.
Times have probably moved on, but there we are.

Guys , as you can see in the previous pictures , original Spark Antenna is made of a very simple design, not big engineering was used to design those , since they are know in the market for a long time.
Those are simples 2.5 and 5.8 antennas.

Mi idea es to attach to the spark 2 more solid (more gain in Db) in order to gain better video reception, better RC response (quick), and of course increment distance, but overall things , to get 100% strong communication.

At this point , having seen the Spark Antenna design I am more enthusiast in perform the modification , because I know that with better antennas I will get better performance in all ways, video distance, responsiveness, and so forth.

I will write down my design , buy elements to perform a "Proof of Concept" and of course I will Upload everything here, being the results best or worst.

Thanks for your comments.

   

Bright Spark Posted at 2018-1-29 10:24
Don't want to be a party pooper, but when I was gainfully employed in the electronics' industry it was absolitely prohibited to handle sensitive equipment such as the spark contains without static discharge protection.
Times have probably moved on, but there we are.

Absolute! At work a "must", at home a "can".

Thanks for your support. We were taught that any damage is likely to be faults developing later on, with components degraded rather than failing at once.
I note many model spares still arrive in static bags.

ANAC PILOT Posted at 2018-1-29 10:56
Guys , as you can see in the previous pictures , original Spark Antenna is made of a very simple design, not big engineering was used to design those , since they are know in the market for a long time.
Those are simples 2.5 and 5.8 antennas.

This could be very interesting. I see forward to more..

Sir, I would not recommend you modified the drone on your own and it may void the warranty. Please fly in a place with good GPS signal and choose a channel with strong signal for better flight performance. Thanks for your support.

DJI Elektra Posted at 2018-1-31 02:20
Sir, I would not recommend you modified the drone on your own and it may void the warranty. Please fly in a place with good GPS signal and choose a channel with strong signal for better flight performance. Thanks for your support.

If only the ocusync system was installed on board of the spark, all these complaints from customers would not have been there. And how much time we still have to wait, your engineers,  to restore the OTG function, that was fully operational until version .15 of the go4 app?

massipos Posted at 2018-1-31 02:43
If only the ocusync system was installed on board of the spark, all these complaints from customers would not have been there. And how much time we still have to wait, your engineers,  to restore the OTG function, that was fully operational until version .15 of the go4 app?

Seems like there is significant cost increase when Occusync is used compared to WiFi. Even Mavic Air does not have it although I do agree Occusync and LB are far more robust technologies than WiFi.

DJI Elektra Posted at 2018-1-31 02:20
Sir, I would not recommend you modified the drone on your own and it may void the warranty. Please fly in a place with good GPS signal and choose a channel with strong signal for better flight performance. Thanks for your support.

Hi Elektra , thanks for your support and advice
Can you get me the technical data , how much is factory antenna DBi Gain?
on DJI Spark of course
Thanks in advance !!!

Bet it already has receivers anyway. Be content with the range mate

I´m not sad or worried about the "range" of my spark.
I also Have a Phantom 4 Pro, a Phantom 3 Pro , and a Mavic Pro, and of course the spark.

I like to "Know" , I like to investigate, I like to research, and I don´t care about warranty or support, since in my country DJI barely exists and the cost of tech services are huge, always is best to buy the part you broke on ebay and replace it by yourself , rather than trying send the drone to DJI tech service.

I live in the country , plenty of trees and thousands acres to test my drones, I am located far away from ANY airport or Aerial highway, here there is no danger to hurt anyone, but the cows.

I am a Systems Engineer , and a electronic technician, that´s why my curiosity !!!

Kind Regards

ANAC PILOT Posted at 2018-1-31 05:04
I´m not sad or worried about the "range" of my spark.
I also Have a Phantom 4 Pro, a Phantom 3 Pro , and a Mavic Pro, and of course the spark.

we hope the mod will be a successful project.

El Diablo Posted at 2018-1-31 06:09
I wouldn't mind to pay more if my drone was safer to fly with less wifi issues and connexion losses...

Yes, but it's probably DJI estimate that there are very few potential customers like you.

El Diablo Posted at 2018-2-1 15:03
Shame... let’s see what Mavic Pro II brings to the game

Thats what I'm holding out for next!

I have done this mod and tested for 2.4 GHz only with one antenna!

Originally I had 1.6 km range in FCC mode and then after the mod I could go upto 2 km.. This is in a suburban area so some interference in 2.4Ghz wifi is expected!  

I have tried that mod and have increased the range somewhat. Originally in FCC mode I could reached upto 1.6 km. And after the mod I could reached upto 2.1 km.

I have to advice you though after you do the modification remember to do a compass calibration. That external antenna going to off balance  the original calibration so make sure to do that before your long distance flight!

I am now in the second stage though that I have installed a 1W amp as well... Still on the testing phase but looking good!   

Also read this thread ! https://mavicpilots.com/threads/aircraft-antenna-mod.21190/

Very nice. But using an amp is somehow cheat.

Yeah had to modify the amp as well since Spark putout 18 dbm signal in CE mode and 26 dbm in FCC mode you will have to add a attenuator to the amp.. I modify the internal circuit of the amp so that it will get less power from spark to avoid saturation. If you want I can explain more! (It is only a three resistor Pi attenuator between frist RF switch and amplification IC ) . My amp only can handle 15 dbm input.


I also have measured RF output of the Spark and the controller  and it is variable gain. Weaker the signals is receive from the controller they both adjust the TX power accordingly. Any external antenna modification with higher gain will likely to exceed EIRP  limit of the country so it is cheating anyways!

EXYY Posted at 2018-2-4 00:10
I have tried that mod [view_image] and have increased the range somewhat. Originally in FCC mode I could reached upto 1.6 km. And after the mod I could reached upto 2.1 km.

I have to advice you though after you do the modification remember to do a compass calibration. That external antenna going to off balance  the original calibration so make sure to do that before your long distance flight!

Incredible !!! Niceee !!!!  Can you publish your range testings on it ?

The "spark" have 2 internal antennas, how do you solve it ? just connect 1 on the outside and let the 2nd. one as factory installed ?

Nice project !! I´ll follow your steps !!!

Just my own personal observations.

The material the Spark is constructed from is transparent to RF so mounting the antennas externally will have next to no benefit for the work involved. There will be instances where, due to orientation of the Spark, signals will be attenuated by other components under the hood of the quad. However these instances will only be momentary as the aspect of the Spark with respect to the operator is continuously changing. Most RC receivers these days use two antennas or a second satellite receiver (diversity reception) to mitigate these problems. This is the same method DJI employed when they changed from a single receive antenna to a diversity system on the Phantom V1.1

Secondly the subject of using antennas with greater gain. Antennas DO NOT amplify signals. For an antenna to have gain over a reference antenna, usually an isotropic or dipole radiator, the radiation pattern is purposefully distorted to favour a particular direction, eg. Lower or higher radiation angles or to produce a beam. This is great for fixed point to point links but inherently problematic for platforms moving in three dimensional space unless some form of real-time tracking method is employed.

ANAC PILOT Posted at 2018-2-4 03:53
Incredible !!! Niceee !!!!  Can you publish your range testings on it ?

The "spark" have 2 internal antennas, how do you solve it ? just connect 1 on the outside and let the 2nd. one as factory installed ?

Yeah! only connected one to the external amp/antenna and other one left  as it is!

Lot of people take advantage of modding the controller antennas to patch antenna for longer range.. Check Cyclone antennas from Titan drones or 4hawks raptor sr etc.. They are very directional.

What I am trying to do is to get more penetration of signal through high interference areas ..

Ya, i modded an old radio tower and installed some antennas..now my spark goes 10 miles...oh i'm kidding!

This looks like an old thread but I wanted to add to this post in the event there are still people interested in modifying the antenna system on the spark. I have posted this same information in other posts several time before.

Be careful about adding any antenna(s) or tracking devices to the top of the spark. The GPS receiving antenna is located almost mid ship under the top cover.  Adding almost anything above this antenna can/will attenuate the GPS signal and could cause a total lost of GPS leading to a fly-a-way.

BMelody Posted at 3-8 08:33
This looks like an old thread but I wanted to add to this post in the event there are still people interested in modifying the antenna system on the spark. I have posted this same information in other posts several time before.

Be careful about adding any antenna(s) or tracking devices to the top of the spark. The GPS receiving antenna is located almost mid ship under the top cover.  Adding almost anything above this antenna can/will attenuate the GPS signal and could cause a total lost of GPS leading to a fly-a-way.

This is the best comment in this forum thank you.

You might be very excited about creating a +10 enhancement with a new antenna. But this might come at a -15 because it compromises other functionality on the drone.

10 - 15 = -5

The other thing to consider is that if something goes wrong and you cause a physical injury to someone and they discover you have tampered with the drone in this way you better make sure have a good lawyer.

ANAC PILOT Posted at 2018-1-29 09:27
[view_image]

Sorry for My Draw , I know I am Awful drawing, but is just a concept...

antennas are too close to each other signals might reflect  what i would do is to put one on top and the other on the bottom and as far as possible from each other.  remember that  the way you got the antennas are vertically polarized and the controller antennas would have to be the same way.