Hello Fellow Yuneec Pilot!
Join our free Yuneec community and remove this annoying banner!
Sign up

Video transmission issues

Nov 14, 2021
Reaction score
I am posting this because maybe other forum members and readers will find it helpful?

With the H520E (European CE-version) I use, the video connection regularly has some hickups: sometimes already from 300 meters but mostly it starts to occur from about 700 meters. As far as I understand from reactions of forum members some more users experience this as a problem.
The Hawks antenna system probably works well and might be able to prevent video interference at these distances, but my objection to it is mainly the hassle of mounting: you have to mount both the antenna itself and then also connect the ST16 with 3 cables. Besides, I find it a bit of a clumsy thing.

Then I got Amazon and Alfa antennas for free from the Netherlands Yuneec seller juist to try out if with one of these the video-issues could be mitigrated. I new hawks (from internet) but was not familiar with these two makes. To test these I looked at the video (on the ST16) during a flight of 1 km (3300 feet) away (I know what VLOS means, this was a simple once-only test).

A kind of dipole from Amazon gave no improvement. The Alfa antennas, on the other hand, showed no interference at all at 700 meters, and given the strength of the ODFM signal I flew twice as far with these (2 km). Also at this double distance there was no video interference at all.

I have very simply presented the results in little graphs. Sorry, the texts are in Dutch, but this is the translation/explanation:

STD Standard antennas
AMAZON Bought through Amazon, 'Gain 6 dB', 2 for 2.4 Ghz only
ALFA Alfa antennas, 2 for 2.4 Ghz, 1 for 2.4/5.8 Ghz

Blue line: Leaving
Green line: Returning

Red --- line: Video interference
Heen: Leaving
Terug: Returning

OFDM: 4 = Full signal, all bars present
1 = Only the dot is present

1027, 1034 and 2034 meters (3369,3382,6673 feet): point of return

The Alfa set of 3 antennas turned out to work well. They are screwed on just like the standard antennas and their weight is low (see photographs). Of course you have to keep the antennas pointed at the drone but as you can see from the result in the graph, this was not a problem. Comparing the Alfa-results at 2034 meters with the standard antennas at 1027 meters I would't be suprised if a distance of 1,5 miles would be possible without videoissues. (my H520E is only 'CE'!)

With these results I think I will use the standard antennas for distances up to about 1500 feet (i.e. most situations), for longer distances I'll use the Alfas.

Perhaps this information is of use to other forum members?

I record every flight on video (by the hdmi-out of the ST16) to study and learn from afterwards, including the flight of over 2 km (6673 feet). Personally I found it rather impressive to see an 'ordinary' H520E CE-version fly to a distance of nearly 7000 feet without any disturbance in video (on the ST16 screen). Of course it's a large file but if anyone would like to see it I will be happy to make it available via a filetransfer site (is than available for a week or so). The other 2 files could be made avialable to, of course.


Last edited:
  • Like
Reactions: Tone-Drone
interesting results. with small antennas very promising for most users. I am going very hard core with 2.4ghz 19dbm wifi 15 inch panels and 5.8ghz 15 inch 23 dbi. preconcept setup got me over 16000ft and back with good dbi readings from the ofdm. getting ready to do another set of runs with updated antenna mount setup. last test the antennas was not set up with the correct height off the ground limiting the distance able to be flown. that had been corrected now with additional mast stems ready to be assembled in to one mast.
Dear Terrence,

Thank you. Yes, that's exactly what I mean: simple, light and they are not expensive. And my European H520E is a 'weak' CE-version! And that is also the reason to post it, it might be of help, I hope. Video without issues!

After the flights I traced them on a internet-site. Vertical beam with is only 16 degree but on a larger distance this appeared to be no problem (just keep the ST16 horizontal). And the horizontal beam-with is 66 degrees, easy enough it seems.

With these antennas the results are, with respect to distance and video, comparable with CE-versions of an ordinary Anafi and a Zino Mini Pro, but a Mavic 3 CE exceeds this by a good margin.
I think it's a pity they didn't improve the (video)transmission. Could it be that almost all the attention is being paid to the development of another drone? In the past few days, there was a mention on the Vertigo site of preregistration on a YUN850EUS. Do you or anyone else know anything about this?

Hard core! You are using antennas who are 'a bit different', right? And FAA-transmittinglevel? What a nice combination!
I would, of course only if it's not too much trouble, like to see this set, do you have a photo of it, or a website with information and photos? Just very curious ....
Hey, can you supply us with an item number or something more? There are alot of items that come up under Alfa antenna. I have the same problem with my drone. It makes flying it in close areas very difficult because of the video latency at short and long distances. I keep the sensors on all the time accept when I'm in wide open airspace.
I did not buy them myself but got them from a Yuneec seller in the Netherlands to see if with these the video-hiccups could be minimized.
As far as I know these are the types:

The central antenna came in a box, so I know for sure it is an Alfa APA-M25 (RP-SMA). For information see:
https://www.amazon.com/Alfa-APA-M25-directional-connector-WL-ANT-157/dp/B00R1PA9EO (and scroll down...)

The other two antennas came without a box and there is, apart from the name 'ALFA', nothing printed on them. But they are 2.4 GHz and there is only one type of this kind to find, so these will be APA-M04 antennas, see:

Possibly the COMPLETE SET was bought as a 'DJI Phantom 3 Standard Quadcopter Drone ALFA RP-SMA Antenna Upgrade Kit',


(I think so because the 3 connecting cables were also present).
Anyway: on this site there is also some more information

The ALFA-print should be directed to the drone, see photo.
Would be nice to know about your experiences with this set of antennas. Is yours a FAA-type?

Last edited:
testing of the equipment was done. all my expectations were exceeded. only thing to do now is build new housing for the equipment that has wheels for easy deployment with all cables connections needed built in.

Members online

Forum statistics

Latest member