Got the DJI FPV HD goggles and 2 air units. Here are my questions: 1) I noticed a USB-C port on the side of the air unit, what is its purpose? 2) Does DJI or another manufacturer sell a longer coaxial cable between the air unit and the camera? I am afraid my second quad build is going to need a slightly longer cable between the air unit and the camera.. 3) Besides activation, what else is the USB-C port on the goggles good for? HDMI in? 4) Last question. I read on a different forum that 90 degree MMCX elbow connectors can increase RF loss, I also noticed that DJI sells straight MMCX antennas (https://store.dji.com/product/dji-fpv-air-unit-antenna-mmcx?vid=82822), are they the same size? Should I even worry about the signal loss? Thank you!

1) The USB-C port is for activating/updating the air unit using the DJI Assistant software.

2) There are no longer coax cables to my knowledge. You will have to mount the air unit close to where your camera is placed.

3) The USB-C port on the goggles has no other function than activating/updating them at this time. It is possible that it will have other functions (such as HDMI in) in the future. The latest firmware added support for the controller to be used in simulators over USB-C.

4) I have had no issues with the elbow MMCX antennas that come with the air unit. I upgraded my goggle antennas though and have seen impressive range improvement.

Kreeze Posted at 1-4 09:38
1) The USB-C port is for activating/updating the air unit using the DJI Assistant software.

2) There are no longer coax cables to my knowledge. You will have to mount the air unit close to where your camera is placed.

Thank you so much for taking the time to answer my questions!

What did you upgrade your antennas to? There seems to be a lot of options out there

Thank you again!

QuadCatper Posted at 1-5 16:54
Thank you so much for taking the time to answer my questions!

What did you upgrade your antennas to? There seems to be a lot of options out there

You're welcome! I upgraded to the TrueRC Singularity stubbies. The antennas the goggles come with are only 50% efficiency so really any upgrade you get will be good (you can learn more about this in KababFPV's video here: https://youtu.be/0NZVbyF7eqg?t=78). I like the ones I got because they're smaller.

Kreeze Posted at 1-5 23:01
You're welcome! I upgraded to the TrueRC Singularity stubbies. The antennas the goggles come with are only 50% efficiency so really any upgrade you get will be good (you can learn more about this in KababFPV's video here: https://youtu.be/0NZVbyF7eqg?t=78). I like the ones I got because they're smaller.

There's more evidence that AXII / TrueRC stubby "upgrades" have no affect. If you are doing long range and would be happy with directional coverage, a pair of TrueRC X-AIR seem promising (2 X-AIR is 4 antennas). It's not recommended to use a single X-AIR like we used to on traditional analog diversity setups.

TechnoCore Posted at 1-6 12:45
There's more evidence that AXII / TrueRC stubby "upgrades" have no affect. If you are doing long range and would be happy with directional coverage, a pair of TrueRC X-AIR seem promising (2 X-AIR is 4 antennas). It's not recommended to use a single X-AIR like we used to on traditional analog diversity setups.

Please link to said "evidence." I can tell you from first-hand experience that my upgrade has drastically improved my range. Also, you are wrong; it is recommended to use a single X-AIR: "It can be used alone, horizontally, connected to the two top SMA." (https://www.racedayquads.com/collections/designed-for-dji-digital-fpv/products/truerc-x-air-5-8ghz-receiver-antenna-for-dji)
Here is a link to a direct comparison between the originals, stubbies, and X-AIRs that proves there is a substantial increase in performance: https://www.youtube.com/watch?v=ReD1kzf5UEY

Sure, and please ease off the harshness.

https://youtu.be/7TCxfRF8mds?t=409

1. Kabab doesn't even use the stubby upgrades, and said nothing about the stock antennas being bad.
2. Furadi doesn't show his OSD, and the video looked worse with the Singularity IMO. I also think testing at 25mw isn't particularly useful unless you intend to fly at that wattage

Yes TrueRC says if you use only 1 X-AIR you should use the top RPSMA, because the top RPSMA are used for both RX and TX back to the air unit. However, by doing this you definitely sacrifice your omni reception...

I just think there's a misconception about the stock antennas being bad, they are actually quite good. If I didn't have a case that fit the stock antennas I might consider the Singularities, but it's still a pricey upgrade for what in my opinion is only a placebo.

If you want to make a video and include the srt OSD file showing a ~10Mbps improvement at 700mw+ I would definitely like to see that.

Interesting discussion.

I would think testing at 25mw is most useful because:
A : There are areas where more than 25mw is illegal. So in order not to have your gear confiscated by officials, only thing you can do to improve range is tweak the antennas.
B: Let's say you are at 700mw, your air unit somehow overheats, it will protect itself by lowering the power to... yes, 25mw.
If you happen to be far out when that happens, my guess is at 25mw the video will stop and the air unit will reboot and you can go and fetch your quad.

I've seen these Youtube video's.
I'm also not convinced the Singularities stubby's were a significant improvement over the stock ones. Not enough to go and buy them just yet.
But what is, it probably has to be a combination of the antenna on your quad AND on the goggles but witch one. So many out there.
Finding the perfect antenna setup is difficult, depends on what you want to do fly through trees, buildings, long range.
Think i'l keep searching.