Covert Drones Installs Amplified 2.5w Antenna Boosters INSIDE your remote.

[Apostol.]

This is the same booster NLD sells.
NLD 2.5W Bi-Di Signal Booster Kit for DJI drones

NLD sells you 2 boosters one for the AC one for the RC.
I have the AC side installed and working, it has 2 leds blue for 5.8ghz red for 2.4ghz, it switches automatically.
Power comes by piggybacking from the battery to a stepdown DC-DC regulator outputs 5.10v and then to the booster which connects to the right side antenna.
So it basically boosts only the right side antenna.
Testing with only the AC booster in FCC mode (not boost mode, nld warns against using boost mode as and i quote "will overgain the booster") installed yielded no appreciable range extension or signal strength. However i get RC signal lost and still have video feed from the drone, so there's that.

One month ago when i received the boosters, the second one was dead, NLD sent me a replacement one, and right now i am having a lot of trouble installing it in the remote.
Its very fiddly, as there is not enough space in the remote, everything is very tightly packed.
After some hours of careful inspection i managed to make all the connections inside the RC.

Basically power comes straight from the battery (4.2 volts), and then to a switch (to switch the booster on and off, otherwise the booster will be always on) then again to a DC-DC (5.10v) regulator and then to the booster.
You have to drill the remote back side to expose the switch.

On the example video they have on their page, the guy connects the booster to the RIGHT antenna essentialy swaping the the two antennas, i presume because the antenna leads are not long enough to reach the booster.

So from the RC board left -> right antenna
Board right -> booster -> left antenna.
Again this boosts only one of the antennas.

The question for me right now is what each antenna on the RC does?
Which one is TX/RX, both of them? only the right one is TX/RX? Which one provides the downlink and which one the uplink?

Connecting the booster to the right socket or the left, shows different behavior from the booster judging from the led's. So the behavior of the two antennas are different.

Here's the problem though, connecting the booster either to the left or right socket and switching it on results on signal degradation judging from the image transmission state on the go 4 app, basically the entire signal line jumps up about 10 dbm to the "poor" state as described in the app. This is with the drone a couple of feet away, not flying.

So something is amiss, haven't done any flying yet, as the controller is in pieces as of writing because of testing, but clearly its not how it should be.

If anyone has any advice on the matter it would be greatly appreciated.

@AZDave you seem to know your stuff, any input on the matter?
Thanks

Attached picture of the booster inside the drone and the RC

 

[Apostol.]

Doing some reading and stumbled upon this thread Mavic2 Radio & Antenna Mods where user beanbubba (rip) was doing exhausting tests.

Seems like the right antenna on the AC does nothing at all after all. And i have connected the booster to the right antenna per nld instructions.So that is clearly wrong, the left antenna must be boosted on AC side.

Also evidently on RC side the right antenna must be used/boosted.

I flew the bird with the booster hooked to the right antenna on the RC and i confirmed my suspicion about the signal, whenever i turn on the booster all hell brakes loose, the image transmision graph goes haywire, the HD and RC icons start flashing.

So at this point either something is wrong with this booster as well, or i must try the left antenna too.

 

[AZDave]

This is the same booster NLD sells.
NLD 2.5W Bi-Di Signal Booster Kit for DJI drones

NLD sells you 2 boosters one for the AC one for the RC.
I have the AC side installed and working, it has 2 leds blue for 5.8ghz red for 2.4ghz, it switches automatically.
Power comes by piggybacking from the battery to a stepdown DC-DC regulator outputs 5.10v and then to the booster which connects to the right side antenna.
So it basically boosts only the right side antenna.
Testing with only the AC booster in FCC mode (not boost mode, nld warns against using boost mode as and i quote "will overgain the booster") installed yielded no appreciable range extension or signal strength. However i get RC signal lost and still have video feed from the drone, so there's that.

One month ago when i received the boosters, the second one was dead, NLD sent me a replacement one, and right now i am having a lot of trouble installing it in the remote.
Its very fiddly, as there is not enough space in the remote, everything is very tightly packed.
After some hours of careful inspection i managed to make all the connections inside the RC.

Basically power comes straight from the battery (4.2 volts), and then to a switch (to switch the booster on and off, otherwise the booster will be always on) then again to a DC-DC (5.10v) regulator and then to the booster.
You have to drill the remote back side to expose the switch.

On the example video they have on their page, the guy connects the booster to the RIGHT antenna essentialy swaping the the two antennas, i presume because the antenna leads are not long enough to reach the booster.

So from the RC board left -> right antenna
Board right -> booster -> left antenna.
Again this boosts only one of the antennas.

The question for me right now is what each antenna on the RC does?
Which one is TX/RX, both of them? only the right one is TX/RX? Which one provides the downlink and which one the uplink?

Connecting the booster to the right socket or the left, shows different behavior from the booster judging from the led's. So the behavior of the two antennas are different.

Here's the problem though, connecting the booster either to the left or right socket and switching it on results on signal degradation judging from the image transmission state on the go 4 app, basically the entire signal line jumps up about 10 dbm to the "poor" state as described in the app. This is with the drone a couple of feet away, not flying.

So something is amiss, haven't done any flying yet, as the controller is in pieces as of writing because of testing, but clearly its not how it should be.

If anyone has any advice on the matter it would be greatly appreciated.

@AZDave you seem to know your stuff, any input on the matter?
Thanks

Attached picture of the booster inside the drone and the RC

Wow! I have to give you huge props ... not the propeller type ... for even attempting something like this, and of course for having the talent to pull it off. Based upon some of your comments, like knowing what dBm is, you seem to be pretty knowledgeable on this kind of stuff yourself.

First of all, I suspect that the reason you didn't see any appreciable improvement in range from the AC booster is that in FCC mode it already puts out enough power for the range that the RC without the booster was capable of supporting. Remember that there needs to be enough signal strength in both directions, and since it appears that you hadn't tested the RC amplifier yet you wouldn't have had that. I could be wrong about this, but that is my suspicion based upon what you've said so far. I would guess that once you get the RC amplifier working you might find that the AC makes a difference as well for long range.

Also, what NLD refers to as "overgaining the booster" is normally called blocking. That's when the input signal is so strong that it drives the amp up against its "headroom". The digital modulation of the signal is of course comprised of 1's and 0's, and when blocking occurs everything looks like a 1. This could be what is happening when you connect up the RC amplifier and test it at such a short range. The amplified signal from the RC could be simply overpowering the front end of the AC to the point that it can't distinguish between those 1's and 0's. The first thing I would try is to move the drone much further away (or move it to the other side of a building) and do your comparison test again.

Regarding the antennas, I don't really know for certain how the two antennas are used, but I suspect that both are used for transmit and both are used for receive (alternating, of course). When both are driven equally in phase the radiation and reception pattern is in the shape of a figure 8 and gives about 3 dB gain broadside to the two antennas, but possibly more importantly gives a very large (maybe 20 dB or more) reduction in gain off the sides (in the plane of the two antennas) that discriminates noise or other interference. As I say, I don't know this for certain, but if I don't keep the RC for my MA2 pointed toward the drone when it is far away I can get a weak signal indication. I think most drone manuals tell you to point the RC toward the drone, although that might be also to keep your body from attenuating the signal.

Since the amplifier in the RC connects to only one of the antennas you lose that 3 dB of directivity gain, but no doubt the amplifer more than makes up for that.

Then again, I could be wrong, but if one antenna was used for transmit and the other for receive I would have thought that NLD would have told you which one to use for the amplifier.

Best of luck to you in getting your setup working. I get an email when a new post is made to this thread, so if you have any further information from your tests please post it. I don't guarantee that I can help, but I'll try.

Lastly, putting an amp in both the AC and RC like you are doing makes total sense to me. Putting an amp only in the RC like some of the other comments doesn't make sense to me at all.

 

[AZDave]

Doing some reading and stumbled upon this thread Mavic2 Radio & Antenna Mods where user beanbubba (rip) was doing exhausting tests.

Seems like the right antenna on the AC does nothing at all after all. And i have connected the booster to the right antenna per nld instructions.So that is clearly wrong, the left antenna must be boosted on AC side.

Also evidently on RC side the right antenna must be used/boosted.

I flew the bird with the booster hooked to the right antenna on the RC and i confirmed my suspicion about the signal, whenever i turn on the booster all hell brakes loose, the image transmision graph goes haywire, the HD and RC icons start flashing.

So at this point either something is wrong with this booster as well, or i must try the left antenna too.

I can easily believe that only one antenna on the AC is functional. It wouldn't make sense to have antenna directivity (that figure 8 pattern I mentioned) on a drone that would often point the pattern notch toward the RC as it flew around.

I still can't say for sure about the RC antennas. However, the fact that AC uses only one antenna strongly suggests that the transmit/receive signals alternate in time, and if so there would be an advantage for the RC to use both antennas in the phased manner I talked about above. There may be some reason why the amplifier in the RC prefers one antenna versus the other, but I can't think of one. Unless you have already moved the drone further away from the RC while testing the RC amplifier, I still think you may simply be overpowering (blocking) the front end of the drone receiver. If you don't want to move the drone further away for some reason, try putting something over it that would either partially block or attenuate the signal. Even some tinfoil might work.

 

[AZDave]

Doing some reading and stumbled upon this thread Mavic2 Radio & Antenna Mods where user beanbubba (rip) was doing exhausting tests.

Seems like the right antenna on the AC does nothing at all after all. And i have connected the booster to the right antenna per nld instructions.So that is clearly wrong, the left antenna must be boosted on AC side.

Also evidently on RC side the right antenna must be used/boosted.

I flew the bird with the booster hooked to the right antenna on the RC and i confirmed my suspicion about the signal, whenever i turn on the booster all hell brakes loose, the image transmision graph goes haywire, the HD and RC icons start flashing.

So at this point either something is wrong with this booster as well, or i must try the left antenna too.

I just thought of something else that might be happening with the RC. This is purely speculative, but what if the amplifier connected to the right antenna in the RC is overpowering the left antenna. The left antenna would still be trying to be active on transmit, and the very strong signal from the right antenna might be feeding back into the transmit circuitry. It all depends upon whether the two antennas get their signal from separate circuits or if one circuit simply feeds a passive splitter.

Is the left antenna connected to the left antenna port during your tests? If so, can you disconnect it? Or possibly even put a resistor (50 to 100 ohms would be my guess) across that connector to terminate it and give the power normally going to the left antenna somewhere to dissipate.

I hesitate to suggest these things because I don't want to be responsible for something that might damage your drone, so please ignore me if you don't feel comfortable trying any of this.

 

[Apostol.]

Wow! I have to give you huge props ... not the propeller type ... for even attempting something like this, and of course for having the talent to pull it off. Based upon some of your comments, like knowing what dBm is, you seem to be pretty knowledgeable on this kind of stuff yourself.

First of all, I suspect that the reason you didn't see any appreciable improvement in range from the AC booster is that in FCC mode it already puts out enough power for the range that the RC without the booster was capable of supporting. Remember that there needs to be enough signal strength in both directions, and since it appears that you hadn't tested the RC amplifier yet you wouldn't have had that. I could be wrong about this, but that is my suspicion based upon what you've said so far. I would guess that once you get the RC amplifier working you might find that the AC makes a difference as well for long range.

Also, what NLD refers to as "overgaining the booster" is normally called blocking. That's when the input signal is so strong that it drives the amp up against its "headroom". The digital modulation of the signal is of course comprised of 1's and 0's, and when blocking occurs everything looks like a 1. This could be what is happening when you connect up the RC amplifier and test it at such a short range. The amplified signal from the RC could be simply overpowering the front end of the AC to the point that it can't distinguish between those 1's and 0's. The first thing I would try is to move the drone much further away (or move it to the other side of a building) and do your comparison test again.

Regarding the antennas, I don't really know for certain how the two antennas are used, but I suspect that both are used for transmit and both are used for receive (alternating, of course). When both are driven equally in phase the radiation and reception pattern is in the shape of a figure 8 and gives about 3 dB gain broadside to the two antennas, but possibly more importantly gives a very large (maybe 20 dB or more) reduction in gain off the sides (in the plane of the two antennas) that discriminates noise or other interference. As I say, I don't know this for certain, but if I don't keep the RC for my MA2 pointed toward the drone when it is far away I can get a weak signal indication. I think most drone manuals tell you to point the RC toward the drone, although that might be also to keep your body from attenuating the signal.

Since the amplifier in the RC connects to only one of the antennas you lose that 3 dB of directivity gain, but no doubt the amplifer more than makes up for that.

Then again, I could be wrong, but if one antenna was used for transmit and the other for receive I would have thought that NLD would have told you which one to use for the amplifier.

Best of luck to you in getting your setup working. I get an email when a new post is made to this thread, so if you have any further information from your tests please post it. I don't guarantee that I can help, but I'll try.

Lastly, putting an amp in both the AC and RC like you are doing makes total sense to me. Putting an amp only in the RC like some of the other comments doesn't make sense to me at all.

Dave first of all thank you for your time writing this response.
Now i understand the "overgaining the booster" part.
The AC and RC is on FCC mode atm, not boost mode so theoretically everything should be fine.
I am aware of the figure 8 pattern of the RC's antennas.

I can easily believe that only one antenna on the AC is functional. It wouldn't make sense to have antenna directivity (that figure 8 pattern I mentioned) on a drone that would often point the pattern notch toward the RC as it flew around.

I still can't say for sure about the RC antennas. However, the fact that AC uses only one antenna strongly suggests that the transmit/receive signals alternate in time, and if so there would be an advantage for the RC to use both antennas in the phased manner I talked about above. There may be some reason why the amplifier in the RC prefers one antenna versus the other, but I can't think of one. Unless you have already moved the drone further away from the RC while testing the RC amplifier, I still think you may simply be overpowering (blocking) the front end of the drone receiver. If you don't want to move the drone further away for some reason, try putting something over it that would either partially block or attenuate the signal. Even some tinfoil might work.

First of all i have the booster connected to wrong antenna on the AC, NLD really dont know their stuff.

Regarding the RC i flew the AC with the booster connected to the right antenna on the rc.
This resulted in massive signal dropoff whenever i powered on the booster, reading the diagram in image transmission settings the noise increases by more than 10dbm, this results in loss of signal and both HD and RC icons blinking.
So something happens when i turn on the booster and the noise floor massively increases.

I just thought of something else that might be happening with the RC. This is purely speculative, but what if the amplifier connected to the right antenna in the RC is overpowering the left antenna. The left antenna would still be trying to be active on transmit, and the very strong signal from the right antenna might be feeding back into the transmit circuitry. It all depends upon whether the two antennas get their signal from separate circuits or if one circuit simply feeds a passive splitter.

Is the left antenna connected to the left antenna port during your tests? If so, can you disconnect it? Or possibly even put a resistor (50 to 100 ohms would be my guess) across that connector to terminate it and give the power normally going to the left antenna somewhere to dissipate.

I hesitate to suggest these things because I don't want to be responsible for something that might damage your drone, so please ignore me if you don't feel comfortable trying any of this.

The one test i did was with the left antenna pluged in (or rather the right physical antenna into the left board socket, and the booster but tha should not matter both antennas are phisically the same).

Id rather not split the connector of the physical antenna since these things are impossible to put back together, maybe i can find a spare connector terminal somewhere in my drawer full of stuff haha.

I have to test more, given that the noise floor increases both when the AC is not in the air and when flying, i can rearrange the connections without having to fly. The goal is to find a combination tha does not increase the noise floor.

Things i know so far:

1. AC side the right antenna does nothing, detailed in the previous thread i linked.So i have to swap the connections on the AC to boost the left antenna that does all the job.
2. connecting the booster on the RC on the right antenna socket while the left antenna is plugged in results in massive noise buildup.
3. This is speculation, but from what i can tell from the other thread, most people boost both RC antennas via extrnal boosters, so boosting only one antenna might not even be viable, i will have to test more.
4. To the OP of this thread and anyone considering that service, this is exactly what i am doing here, its the same booster/board, so my testing will prove how viable this mod is.

I will report back my findings

 

[AZDave]

Dave first of all thank you for your time writing this response.
Now i understand the "overgaining the booster" part.
The AC and RC is on FCC mode atm, not boost mode so theoretically everything should be fine.
I am aware of the figure 8 pattern of the RC's antennas.


First of all i have the booster connected to wrong antenna on the AC, NLD really dont know their stuff.

Regarding the RC i flew the AC with the booster connected to the right antenna on the rc.
This resulted in massive signal dropoff whenever i powered on the booster, reading the diagram in image transmission settings the noise increases by more than 10dbm, this results in loss of signal and both HD and RC icons blinking.
So something happens when i turn on the booster and the noise floor massively increases.

The one test i did was with the left antenna pluged in (or rather the right physical antenna into the left board socket, and the booster but tha should not matter both antennas are phisically the same).

Id rather not split the connector of the physical antenna since these things are impossible to put back together, maybe i can find a spare connector terminal somewhere in my drawer full of stuff haha.

I have to test more, given that the noise floor increases both when the AC is not in the air and when flying, i can rearrange the connections without having to fly. The goal is to find a combination tha does not increase the noise floor.

Things i know so far:

1. AC side the right antenna does nothing, detailed in the previous thread i linked.So i have to swap the connections on the AC to boost the left antenna that does all the job.
2. connecting the booster on the RC on the right antenna socket while the left antenna is plugged in results in massive noise buildup.
3. This is speculation, but from what i can tell from the other thread, most people boost both RC antennas via extrnal boosters, so boosting only one antenna might not even be viable, i will have to test more.
4. To the OP of this thread and anyone considering that service, this is exactly what i am doing here, its the same booster/board, so my testing will prove how viable this mod is.

I will report back my findings

It sounds like you know a lot more about this stuff than most folks do.

Based upon what you said so far, it sounds like you have the AC properly figured out. Good job. Too bad NLD had it backwards.

For the RC, it sounds more and more like you either need to terminate the non-amplified port or, as you say, put another amplifier on it. At this point I'd bet money that the 10 dBm noise increase is coming from the amplifier feeding back into the other port.

Best of luck and I will be very interested in your progress.

 

[Interficiam Stercore]

I was told by a mod installer, that, on the remote, the LEFT antenna is the reciever and the RIGHT is the transmitter. This was on an Air 2 remote

 

[Jagerbomb52]

Luke from Covert Drones is a paid sponsor of one of the forums (Autel). Maybe here also but not sure. I can tell you the man has been doing this kind of business for years and he is very well respected for his workmanship, service before and after sales. If anyone had a problem he solved it as soon as possible. Many, many people have giving him top notch reviews so if he is charging $500 bucks for a professional job then it would be well worth it to have him do it. It will work right out of the gate as advertised or he would not be doing it.

 

[AZDave]

I was told by a mod installer, that, on the remote, the LEFT antenna is the reciever and the RIGHT is the transmitter. This was on an Air 2 remote

That may indeed be true, but there is a LOT of conflicting information out there. Some say that transmit and receive for both control and video use different antennas. Some say that one antenna uses transmit and receive for control and the other antenna uses transmit and receive for video. Some say that both antennas are used in phase for everything. There may even be differences depending upon the model of drone.

Here's a link to an old forum thread that says that the left antenna (not sure which DJI model is referred to) does both transmit and receive for both control and video while the right antenna is used for what they call MIMO, which is basically a term for a secondary receive-only antenna spaced far enough away from the main antenna that during receive the board electronics can discriminate among multiple incoming signals that occur due to bounces off adjacent objects. It does so by sensing the phase difference between the signals because of the spacing (path difference) between the two antennas, which at these frequencies is a significant portion of a wavelength.

Mavic Pro Controller antennas and function

You've always got to remember that running a transmitter into ' No ' Aerial ( or faulty aerial ) could destroy the output stage of the transmitter or some of the associated components. The longer you run it, the greater the risk. I learned THAT sad lesson a few years ago when doing FPV on my P2's!

mavicpilots.com

I'm not saying that I know which is the case because I don't, but as that old thread points out, it can be dangerous to operate either the drone or the controller in a way that it transmits into an open port. ALWAYS have some sort of load on a transmit port ... either an antenna or a proper resistor (my guess would be 50 to 100 ohms but that is purely a guess).

 

[Apostol.]

Luke from Covert Drones is a paid sponsor of one of the forums (Autel). Maybe here also but not sure. I can tell you the man has been doing this kind of business for years and he is very well respected for his workmanship, service before and after sales. If anyone had a problem he solved it as soon as possible. Many, many people have giving him top notch reviews so if he is charging $500 bucks for a professional job then it would be well worth it to have him do it. It will work right out of the gate as advertised or he would not be doing it.

Maybe he is doing something different from what i am doing, although i cant imagine what.

It sounds like you know a lot more about this stuff than most folks do.

Based upon what you said so far, it sounds like you have the AC properly figured out. Good job. Too bad NLD had it backwards.

For the RC, it sounds more and more like you either need to terminate the non-amplified port or, as you say, put another amplifier on it. At this point I'd bet money that the 10 dBm noise increase is coming from the amplifier feeding back into the other port.

Best of luck and I will be very interested in your progress.

I was told by a mod installer, that, on the remote, the LEFT antenna is the reciever and the RIGHT is the transmitter. This was on an Air 2 remote

Don't know about the air 2 but my observations on the mavic 2 thus far are:

With both the antennas of the AC disconnected (AC 5 feet away from the controller) i tried the following. (no booster on the RC, straight from the board to the antennas):

1. Both antennas installed everything normal
2. Disconnecting the LEFT antenna of the remote, result: The remote wont connect to the drone.
3. Disconnecting the RIGHT antenna of the remote, result: The remote connects to the drone but the HD icon has only one bar out of five.

So some conclusions may be made from the above observations, but i do not have the knowledge to accurately assess and draw any.
I can speculate though that both ports have to be connected to something.


About the booster:
I tried every combination possible.
On the right port/antenna or the left port/antenna, with or without the other port connected.
Eveytime i switch on the booster the image transmission state graph goes haywire.No matter what i do.

Booster switched on :

Booster switched off/no booster installed :

 

[Apostol.]

Continuing from last post
That's 15dbm difference. Again i dont have the knowledge to explain this, but clearly something is not right

This is a screen cap from the youtube video on the nld page where the guy flies 12 km out:



So at this point i am in a dead end.

1. Its again a faulty booster.
2. Something is wrong with my setup: Quite unlikely, checked with the multimeter every solder point on the power side of things, everything checks out, high resistance nowhere to be found. I even powered the booster from an external 18650 battery. Same thing.
3. Checked the pigtail leads, all of them are proper.
4. The DC-DC voltage regulator is somehow to blame: Outputs 5.10 volts with no load, drops voltage as expected to 5.08-5.07 when the booster is connected. I did not however measure how many amps the booster is drawing.

The only thing that bothered me is that disconnecting the negative terminal of DC-DC converter did not affect the booster, it stayed powered on, i presume the ground of the pigtail lead to the board acts as the negative terminal, electrons will follow the path of least resistance, maybe that is somehow what causes the noise.

The negative wire that goes to input of the regulator is attached to a screw where it touches the common ground of the board. Tried to connect it directly to battery, no difference.

This is a photo of the temp wiring, scribbled on the picture if anyone wants to take a look:




And one last thing, i have to connect the booster that's in the drone to the LEFT board port to boost the LEFT antenna.
Sadly the pigtail cable NLD provided is about one inch too short for that, i have to source longer cables:



Lastly i would like to comment on NLDs support for their product, they did send me another booster when the first one was doa, BUT they have absolutely no documentation for their product.
Even the example videos they have on their site are plain wrong, the guy installed the booster on top of the intake fan depriving it of air from the intake vents, that is just wrong.

I will be contacting their support again pointing them to this thread, i simply cant explain them the whole thing again, its written here in detail.


If anyone has any suggestions on the matter please comment.

Thank you all again.

 

[cgmaxed]

No .. .that's not how it works. There is no such thing as a "frequency amplifier" either, and your post that you apparently deleted (I got the email with the post but it's gone now) with the quote about IF stages in a superheterodyne receiver, while perfectly accurate, has nothing to do with the topic at hand.

I'll say it for the third time here in this thread, any amplifier for a received signal amplifies the noise every bit as much as it does the desired signal ... except as I said above in the very unlikely situation that the amplifier has a narrower bandwidth than the drone receiver already does. The net result is a louder signal AND louder noise, and the ratio of signal to noise is all that is important. If the signal is so weak without the amplifier that it's down in the noise and can't be properly decoded is STILL going to be under the noise after both are amplified. This is really, really basic stuff that you're not getting.

And in many cases, and especially at these frequencies, it can be really difficult to design an amplifier with a low enough noise figure that it doesn't actually degrade the signal-to-noise situation for the receiver.

I wouldn't keep making such an issue out of this here except that I truly hate to see misinformation being quoted as fact. Unless the stock drone ALREADY puts out a stronger signal than the controller does (which nobody here seems to know) then these $500 amplifiers are only improving one side of what needs to be a two way communication link. I may not be able to convince you of the physics involved here, but maybe I can help somebody else think a little deeper about it. This indeed a hobby, but it's fundamentally a technical hobby and we should be talking actual science instead of whatever it is you're posting.

You convinced me. Thanks for responding and helping me understand what is really going on with these amplifiers.

 

[cgmaxed]

Continuing from last post
That's 15dbm difference. Again i dont have the knowledge to explain this, but clearly something is not right

This is a screen cap from the youtube video on the nld page where the guy flies 12 km out:
View attachment 133865


So at this point i am in a dead end.

1. Its again a faulty booster.
2. Something is wrong with my setup: Quite unlikely, checked with the multimeter every solder point on the power side of things, everything checks out, high resistance nowhere to be found. I even powered the booster from an external 18650 battery. Same thing.
3. Checked the pigtail leads, all of them are proper.
4. The DC-DC voltage regulator is somehow to blame: Outputs 5.10 volts with no load, drops voltage as expected to 5.08-5.07 when the booster is connected. I did not however measure how many amps the booster is drawing.

The only thing that bothered me is that disconnecting the negative terminal of DC-DC converter did not affect the booster, it stayed powered on, i presume the ground of the pigtail lead to the board acts as the negative terminal, electrons will follow the path of least resistance, maybe that is somehow what causes the noise.

The negative wire that goes to input of the regulator is attached to a screw where it touches the common ground of the board. Tried to connect it directly to battery, no difference.

This is a photo of the temp wiring, scribbled on the picture if anyone wants to take a look:
View attachment 133866



And one last thing, i have to connect the booster that's in the drone to the LEFT board port to boost the LEFT antenna.
Sadly the pigtail cable NLD provided is about one inch too short for that, i have to source longer cables:
View attachment 133867


Lastly i would like to comment on NLDs support for their product, they did send me another booster when the first one was doa, BUT they have absolutely no documentation for their product.
Even the example videos they have on their site are plain wrong, the guy installed the booster on top of the intake fan depriving it of air from the intake vents, that is just wrong.

I will be contacting their support again pointing them to this thread, i simply cant explain them the whole thing again, its written here in detail.


If anyone has any suggestions on the matter please comment.

Thank you all again.

I don't have any suggestion, except to keep us updated, if you make any progress. Thanks.

 

[nolimitdronez]

Continuing from last post
That's 15dbm difference. Again i dont have the knowledge to explain this, but clearly something is not right

This is a screen cap from the youtube video on the nld page where the guy flies 12 km out:
View attachment 133865


So at this point i am in a dead end.

1. Its again a faulty booster.
2. Something is wrong with my setup: Quite unlikely, checked with the multimeter every solder point on the power side of things, everything checks out, high resistance nowhere to be found. I even powered the booster from an external 18650 battery. Same thing.
3. Checked the pigtail leads, all of them are proper.
4. The DC-DC voltage regulator is somehow to blame: Outputs 5.10 volts with no load, drops voltage as expected to 5.08-5.07 when the booster is connected. I did not however measure how many amps the booster is drawing.

The only thing that bothered me is that disconnecting the negative terminal of DC-DC converter did not affect the booster, it stayed powered on, i presume the ground of the pigtail lead to the board acts as the negative terminal, electrons will follow the path of least resistance, maybe that is somehow what causes the noise.

The negative wire that goes to input of the regulator is attached to a screw where it touches the common ground of the board. Tried to connect it directly to battery, no difference.

This is a photo of the temp wiring, scribbled on the picture if anyone wants to take a look:
View attachment 133866



And one last thing, i have to connect the booster that's in the drone to the LEFT board port to boost the LEFT antenna.
Sadly the pigtail cable NLD provided is about one inch too short for that, i have to source longer cables:
View attachment 133867


Lastly i would like to comment on NLDs support for their product, they did send me another booster when the first one was doa, BUT they have absolutely no documentation for their product.
Even the example videos they have on their site are plain wrong, the guy installed the booster on top of the intake fan depriving it of air from the intake vents, that is just wrong.

I will be contacting their support again pointing them to this thread, i simply cant explain them the whole thing again, its written here in detail.


If anyone has any suggestions on the matter please comment.

Thank you all again.

Hello,

We have looked into your order, and you ordered a FCC booster kit for a CE system.
That is the reason for the issues that you are experiencing.

If your devices are CE, then the booster kit has to be CE as well.
Now that you have a FCC booster kit for a CE drone, here is what you can do to resolve the matter:

Open NLD and apply FCC mode WITHOUT BOOST!
It is very important that you do not enable boost as it will over gain the amplifier.

Please remember that every time you do a firmware flash, you will have to enable FCC mode.

The booster outputs 2.5W no matter if it is CE or FCC mode so there is nothing won by using FCC on a CE system.
We also state that on the product page and that is also why we offer the booster kit in both FCC and CE configurations.

When using this hardware mod it should not be necessary to also use a software mod.
However, since you have the FCC version for a CE system, you will have to use the software mod to enable FCC mode.

I hope that this will shed some light on what is going on.

Finally, as response to the original poster regarding this company installing booster in the remote only.
This simply does not make any sense at all to install only a booster in the RC.

If the drone does not have a booster kit installed it does not do much good if the RC has a booster installed.
The reason is that the signal also has to be boosted from the drone to reach the RC.

That is why our booster kit is awesome because it boost both the drone and the RC.

Agreed that the install video is not very good, but we have had some new professional videos created that can be found on our YouTube channel:

https://www.youtube.com/channel/UC94ESMOYI63Pji7AHiEOAJg

The product page will also be updated with these videos:

NLD 2.5W Bi-Di Signal Booster/Amplifier Kit v2 for DJI drones

2.4GHz & 5.8GHz dual band signal booster kit for DJI drones in particular but can be used with anything that uses WiFi for transmission

nolimitdronez.com

/C

 

[Apostol.]

Hello,

We have looked into your order, and you ordered a FCC booster kit for a CE system.
That is the reason for the issues that you are experiencing.

If your devices are CE, then the booster kit has to be CE as well.
Now that you have a FCC booster kit for a CE drone, here is what you can do to resolve the matter:

Open NLD and apply FCC mode WITHOUT BOOST!
It is very important that you do not enable boost as it will over gain the amplifier.

Please remember that every time you do a firmware flash, you will have to enable FCC mode.

The booster outputs 2.5W no matter if it is CE or FCC mode so there is nothing won by using FCC on a CE system.
We also state that on the product page and that is also why we offer the booster kit in both FCC and CE configurations.

When using this hardware mod it should not be necessary to also use a software mod.
However, since you have the FCC version for a CE system, you will have to use the software mod to enable FCC mode.

I hope that this will shed some light on what is going on.

Finally, as response to the original poster regarding this company installing booster in the remote only.
This simply does not make any sense at all to install only a booster in the RC.

If the drone does not have a booster kit installed it does not do much good if the RC has a booster installed.
The reason is that the signal also has to be boosted from the drone to reach the RC.

That is why our booster kit is awesome because it boost both the drone and the RC.

Agreed that the install video is not very good, but we have had some new professional videos created that can be found on our YouTube channel:

https://www.youtube.com/channel/UC94ESMOYI63Pji7AHiEOAJg

The product page will also be updated with these videos:

NLD 2.5W Bi-Di Signal Booster/Amplifier Kit v2 for DJI drones

2.4GHz & 5.8GHz dual band signal booster kit for DJI drones in particular but can be used with anything that uses WiFi for transmission

nolimitdronez.com

/C

Your response here is very welcome.

You are right i did purchase the FCC version, theoretically there should be no gains as you state, but also no problems if the drone is flashed to FCC.

Regarding FCC vs CE, yes the drone is a CE drone but it is on FCC mode, not BOOST mode.
I did not use your software to change it to FCC, but i am certain that my drone is on FCC not BOOST, i recently reflashed FCC just to be sure.

So per your instructions i will try your software (which costs 40 euros) to flash FCC mode and try that to see what happens, although i do not have high hopes.

Another question for you,
On the AC side, which antenna do you recommend boosting? The LEFT antenna or the RIGHT antenna?
In your videos, including the new ones, the RIGHT antenna is boosted.
There has been strong evidence and documented in this forum that the LEFT antenna does all the work and should be boosted.
The U.FL cable you supply is to short to reach the RIGHT antenna port.
Have you performed any tests on the mavic 2 to determine which antenna is worth boosting?

Finally on the RC side, i have concluded that the booster should be connected to the RIGHT labeled port on the board, just like your videos.
Do you agree?

Thanks.

 

[Apostol.]

NLD didnt reply here but i went ahead and did what they suggested anyways and purchased a license for the NLD Client, enabled FCC from THEIR software.
Results? The same as before:

Booster on :


Booster off:


Like how would there be any difference? Because of their software?
FCC is FCC period.
Refund requested.
I know i had just FCC enabled before from drone-hacks, and NOT BOOST mode.
Yet somehow THEIR FCC mode would be different.. Please, give me a break.
Anyways at this point i will rip the boosters of the AC and the remote.
Im done.

 

[nolimitdronez]

NLD didnt reply here but i went ahead and did what they suggested anyways and purchased a license for the NLD Client, enabled FCC from THEIR software.
Results? The same as before:

Booster on :
View attachment 133910

Booster off:
View attachment 133911

Like how would there be any difference? Because of their software?
FCC is FCC period.
Refund requested.
I know i had just FCC enabled before from drone-hacks, and NOT BOOST mode.
Yet somehow THEIR FCC mode would be different.. Please, give me a break.
Anyways at this point i will rip the boosters of the AC and the remote.
Im done.

I replied to your question before.
All I wanted was to make sure that you were in FCC mode.

It doesn't matter what Software does it, fcc mode is fcc mode and that is it.

I saw your support ticket and I told the support guy to tell you that from your pictures you were in fcc mode.

You can of course get a full refund, because you did not have to buy a license to apply fcc.

I don't know what other software does and that is why I asked if you had enabled fcc in nld.

Regarding the signal, online one antenna is needed to be boosted.
When the RC signal can not reach the drone, all RC functions are routed over occusync which is the video feed.

I will have support give you a detailed answer on how it should be installed properly.

Be aware that if the power wirre is going over or under the amplifier, then the magnetic field from the wire will interfere with the amplifier and cause noise.

If that is the case here I don't know.

/C

 

[Apostol.]

I replied to your question before.
All I wanted was to make sure that you were in FCC mode.

It doesn't matter what Software does it, fcc mode is fcc mode and that is it.

I saw your support ticket and I told the support guy to tell you that from your pictures you were in fcc mode.

You can of course get a full refund, because you did not have to buy a license to apply fcc.

I don't know what other software does and that is why I asked if you had enabled fcc in nld.

Regarding the signal, online one antenna is needed to be boosted.
When the RC signal can not reach the drone, all RC functions are routed over occusync which is the video feed.

I will have support give you a detailed answer on how it should be installed properly.

Be aware that if the power wirre is going over or under the amplifier, then the magnetic field from the wire will interfere with the amplifier and cause noise.

If that is the case here I don't know.

/C

Thanks for the reply

As i do the testing the remote is partially disassembled like so:


no wires are going under or over the booster.

I did notice something on your NEW WELL DONE videos
What is this thing?

I have not installed it, in the previous videos you had on your site THE GUY DID NOT INSTALL IT.
I followed that video, as you didnt have any instructions anywhere except that badly shot video.
And i repeat the guy on that video did not install this.
What does it do? Is it needed?
I cant find it anywhere, i may have misplaced it.

 

[AZDave]

The thing that strikes me here in this thread about all of this is how completely poorly almost everything about the operation of these amplifiers and how they interact with the stock hardware is explained. Things would make so very much more sense if nld started out by clearly explaining how the original hardware worked and what gets changed when their amplifiers are added. Based upon what I've seen here, they don't even really explain how to connect their gear in the first place, much less how things work afterward.

I'm a degreed electrical engineer with an RF background and a proficient ham radio enthusiast who has designed some of my own gear, and if I was serious about buying one of these amplifier packages (I'm not) I would still have a ton of questions.

I suspect other vendors are even worse.

Apostol has a better knowledge base and has put far more effort into this than any vendor has the right to expect and he's still having major problems. That just doesn't seem right to me.