Raf_IZ0QWM Posted at 6-7 07:54
Thank you Stephen,
in fact, it is assumed that those who modify the drone in some part of it know what they are doing.
But you know it well ... we always try to do something to fix, touch, disassemble what we have. They are our toys and they are beautiful for that too.

"we always try to do something to fix, touch, disassemble what we have."
Absolutely.

I actually purchased a second drone so I could take one apart and still have one to fly.

I'm seriously considering putting the parts of drone I've taken apart into a more conventional drone frame. While I'm doing this, I could also replace the antenna in the drone with circular polarized antenna. Do you think there would be much a benefit if both the goggle antennas and the drone antennas were circular polarized?

Thanks for adding so much technical information. I really enjoy learning about this sort of stuff.

Raf_IZ0QWM Posted at 6-7 07:41
So, today I've done some more test with the goggles antennas and with one home made.

This is the VSWR of the original antenna:

The VSWR seems fine on the stock antennas. 1.5 or under for the frequencies you want. A lower Q than yours though. Your homemade one is def pulling more signal also.

Do you have the TrueRC dualities? I wonder how they would compare on your setup.

anethema Posted at 6-7 19:49
The VSWR seems fine on the stock antennas. 1.5 or under for the frequencies you want. A lower Q than yours though. Your homemade one is def pulling more signal also.

Do you have the TrueRC dualities? I wonder how they would compare on your setup.

Unfortunately I don't have the TrueRCs. I would love to try them.

Oh the antenna has been done in a few minutes, just to test that can be do more with simple.
Ehm mine has a lower Q, it's wideband in 5.8GHz.  High Q indicates narrowband, low Q indicates wideband.
Usually the ground planes have a wideband, you can achive cutting the radials in the right way.

I preferred to have a ground plane because I realized that the stock antennas have a problem when you screw them.
If you screw them too much it changes the VSWR a lot and obviously, even when they are very slow.
In short ... the yield can change easily.

BUT what the stock antennas and TrueRCs certainly have, which are compact.
But as you know, compact does not always mean performing well.

Duane Degn Posted at 6-7 08:44
"we always try to do something to fix, touch, disassemble what we have."
Absolutely.

You would need circular polarization antennas on the remote controller as well.

Maybe you could use trueRC everywhere.
With some nice changes it can be done.

Raf_IZ0QWM Posted at 6-7 20:14
You would need circular polarization antennas on the remote controller as well.

Maybe you could use trueRC everywhere.

"You would need circular polarization antennas on the remote controller as well."

Right. I hadn't thought about the controller antenna. Changing these antenna would be too hard. All the antenna on the drone (except GPS) use UFL connectors. The same is true for the two controller antenna.

I think I will delay swapping antenna type. I started pricing antennas and counting up how many I'd need. I don't think I want to put that much more money into this project right now. Eventually, I'll follow some of the antenna making tutorials and learn to make my own.

I already have a lot of work to do to fit the DJI FPV drone parts into a normal frame.

Raf_IZ0QWM Posted at 6-7 20:12
Unfortunately I don't have the TrueRCs. I would love to try them.

Oh the antenna has been done in a few minutes, just to test that can be do more with simple.

For sure. Low Q, wideband.

Ya I'm tempted to put a couple of vertically spaced 2.4 or 5.8GHz sectorals on my tower and just run a couple cables down to a comfy sitting/flying station at the bottom.

I only put 56 feet of it up but I could put the rest of it up to get around 95 feet.

I'd sure get some wild range then! Battery would definitely be the limiter at that point heh.

Raf_IZ0QWM Posted at 6-7 07:54
Thank you Stephen,
in fact, it is assumed that those who modify the drone in some part of it know what they are doing.
But you know it well ... we always try to do something to fix, touch, disassemble what we have. They are our toys and they are beautiful for that too.

Hi there Raf. You are very much welcome and thank you for sharing your valued insights with regards to this matter. Have a safe and a happy flying always.

anethema Posted at 6-8 20:13
For sure. Low Q, wideband.

Ya I'm tempted to put a couple of vertically spaced 2.4 or 5.8GHz sectorals on my tower and just run a couple cables down to a comfy sitting/flying station at the bottom.

ahahahah you're crazy.   Where do you want to go??  
I think at that point you would have the problem of cable leakage. To use all the power you should go and transmit on your trellis.

Raf_IZ0QWM Posted at 6-9 00:35
ahahahah you're crazy.   Where do you want to go??  
I think at that point you would have the problem of cable leakage. To use all the power you should go and transmit on your trellis.

I'd like to pull the circuitry out of a battery and replace the battery with a home-made larger pack, see how long and far it could fly for fun. Be interesting to go out 10km and back!

Hi guys this is the rear antenna

Raf_IZ0QWM Posted at 6-13 12:34
Hi guys this is the rear antenna

Fantastic!
Thank you.
Is there a thin trace on the back side of the PCB inline with the smaller branch of the antenna?

Based on the wires, I'm guessing the LEDs are on the same PCB. Is this right? It would be great to see photos of both sides of the complete PCB.

You're right.
This is the other side of the pcb

Raf_IZ0QWM Posted at 6-7 20:14
You would need circular polarization antennas on the remote controller as well.

Maybe you could use trueRC everywhere.

Hello Raffaello!
Do you have any opinion on how to properly connect Lumenier AXII HD 5.8GHz Antenna Combo Set? DJI Goggles Version 2 & DJ AIR Unit
Thanks for the help!

Ginmax Posted at 6-14 23:31
Hello Raffaello!
Do you have any opinion on how to properly connect Lumenier AXII HD 5.8GHz Antenna Combo Set? DJI Goggles Version 2 & DJ AIR Unit
Thanks for the help!

Oh @Ginmax those antennas are for the 5.8GHz band only and have circular polarization.
The claimed gain is for 8.2dBi patches and 2.2dBi small antennas.

So if you really want to use them with DJI FPV drone, you need to set the frequency on the drone to 5.8GHz only.
Then, please, at least instead of the two small antennas that mount below, use the original ones from the drone instead.
At least, this way you can preserve linear polarization on some part of the MIMO.
So much the gain of small antennas is worse than stock ones which are 3dBi.

Raf_IZ0QWM Posted at 6-14 23:49
Oh @Ginmax those antennas are for the 5.8GHz band only and have circular polarization.
The claimed gain is for 8.2dBi patches and 2.2dBi small antennas.

Interesting that the gain of the duality antennas is listed as

    Gain: 1.7dBic @2.4GHz, 2.8dBic @5.8GHz

In both bands less than the stock, yet all the tests I've seen in videos show them working better, even with the wrong polarization.

I’m currently using the stubby duality; pricey, noticed more consistent feed, did several range test easily 1000 ft more but reliability was what I felt mattered most; trust these over stock

anethema Posted at 6-15 09:58
Interesting that the gain of the duality antennas is listed as

    Gain: 1.7dBic @2.4GHz, 2.8dBic @5.8GHz

which antennas are you talking about?  
If you talk about those of TrueRC, they know how to set them very well on frequency. They take great care.
Which means there are no reflected waves.
This is a gain for the transmission but also for the transmitter which suffers less and lasts longer.
https://www.antenna-theory.com/definitions/vswr.php

Dji fpv rc antenna upgrade  ???  Nevermind Goggle upgrade I need rc range ..

luciens Posted at 2021-5-31 05:02
Nevertheless, that seems to be what it's doing. This is how the old DJI goggles worked on Ocusync 2.0 when connected to the mavic pro 2, for example. The back-and-forth to the aircraft was all done through the controller.
There's no latency with a repeater - it's just a retransmission of a received signal on another frequency, there's no digital processing of the RF involved. It's a tried-and-true method that can be done with all analog circuitry in radio that's been around forever.

That is not correct at all. The goggles are linked directly to the Mavic Pro on the White goggles. They are connected as a secondary controller and the drone can be flown by the goggles. (Camera)

Anytime you have to link goggles to a drone means that the google video comes directly from the drone.

This includes the FPV drone.

I think people get confused as the goggles do talk to the controller. But that is for programming and setting features.

vitaediluculum Posted at 1-11 04:36
Dji fpv rc antenna upgrade  ???  Nevermind Goggle upgrade I need rc range ..

sorry for the necro, but have you found anything that will help the remote controller with better penetration??

luciens Posted at 2021-5-30 05:33
For the FPV drone, I'm pretty sure the RC link and video both are handled by the controller and not the goggles. So upgrading the antennas on the goggles won't make any difference - they just link to the controller, I believe.

For the air unit/caddx digital system, the transceivers in the goggles themselves definitely directly handle the video, so in that application better antennas might help. Reportedly the 5.8ghz patch antennas from iFlight, etc., significantly increase the quality of the video connection. But I haven't tried those on my V2 goggles.

The signals for the remote are actually separate signals in flight. Your not completely wrong though. The goggles and the remote do communicate, but the HD video feed is separate. The remote sends information to your goggles so you can see all your flight information. I would have thought exactly what you were saying, but if you turn the remote off and leave the drone on and the goggles on, you still get a video feed with an RC remote disconnect warning. This is why, when people use cheap aftermarket antenna, the drone can malfunction.

Stellios Posted at 2021-6-1 23:29
what's the simple hack?? Most of the hacks out there that I have tried don't work. There is a company that sells some app that puts the drone in FCC mode but that hack works for the Euro people but here in the USA there's really no hack that's worth it for us here in the USA.

I'd like  it if DJI would just give us the option in the Manu settings to do this.

I conncur from the uk

I successfully use Lumenier Dual-Mox antennas. But I did them my way. I put rp-sma plugs angled 90 degrees and a shorter LMR-195 UF cable. The range relative to stock antennas has been significantly improved for both frequencies.