H520E - ST16E transmission questions

[busx]

Is there someone who has knowledge about the transmission used by the H520E? I would be very pleased to understand a bit more of the matter.
I tried to find out things, but can't find much information.

Is this right:

Transmission is by OFDM 2.4 GHz for data as well as for video, and the 5,8 GHz small round antenna is only for communication with internet (mostly downloading a map)?

If so:

Then both rod antennas are used for 2,4 GHz? Is one used for RC and the other for video, or are the signals mixed in any way?

Is it correct that the communication works with vertical polarization? (the antennas of the H520E are vertically mounted, I think).

If so, should you then for optimal transmission (and optimal distance) make sure that both 2.4 GHz-antennas (on the ST16E) are also positioned vertical?

Yuneec states there is a redundant signal to increase transmission security. What kind of signal is meant, could this be explained without being to technical?

Many thanks!

 

[Vaklin]

Start from here...

Here is better...

 

[busx]

Dear Vaklin,

Thanks for your links. I already read them, and thought I 'd understand OFDM more or less. Maybe I 'm wrong, and have missed the link between OFDM and my other questions? But, still I do not know or understand the relation (is there a relation?) of OFDM, polarization and the redundant signal.

 

[Vaklin]

I didn't understand your question well. Sorry. Polarization is related to the antenna type and is not directly connected to the type of modulation. The manufacturer can choose one or another, usually, this depends on the free space for aerials.




In the attached PDF you can see what antenna is for what. For sure, you can't maintain strong parallelism between sender's and receiver's antennas. Of course, better is to be not perpendicular, as polarization is linear, but nothing more.

Redundancy is achieved with redundancy. You can send 5 times more information than the vehicle wants to get to be on a safe flight. More that, the uplink is not strong uninterrupted, the vehicle has some ability to maintain the task or to hover if doesn't know to do for some time.

If this doesn't satisfy your curiosity I can't say more about the topic.

 

[WTFDproject]

Is there someone who has knowledge about the transmission used by the H520E? I would be very pleased to understand a bit more of the matter.
I tried to find out things, but can't find much information.

Is this right:

Transmission is by OFDM 2.4 GHz for data as well as for video, and the 5,8 GHz small round antenna is only for communication with internet (mostly downloading a map)?

If so:

Then both rod antennas are used for 2,4 GHz? Is one used for RC and the other for video, or are the signals mixed in any way?

Is it correct that the communication works with vertical polarization? (the antennas of the H520E are vertically mounted, I think).

If so, should you then for optimal transmission (and optimal distance) make sure that both 2.4 GHz-antennas (on the ST16E) are also positioned vertical?

Yuneec states there is a redundant signal to increase transmission security. What kind of signal is meant, could this be explained without being to technical?

Many thanks!

I do not know for H520E. But if it is the same as earlier models;

"Then both rod antennas are used for 2,4 GHz? Is one used for RC and the other for video, or are the signals mixed in any way?
Is it correct that the communication works with vertical polarization? (the antennas of the H520E are vertically mounted, I think)."
The rod antennas are both 2.4Ghz. The 2.4 GHz is normally for control of the drone and manual control of the camera gimbal. The 5.8 GHz is Normally the video signal and control of the camera video related features. (See the last comment for why "normal" does not mean "always".)

"If so, should you then for optimal transmission (and optimal distance) make sure that both 2.4 GHz-antennas (on the ST16E) are also positioned vertical?"
Aligning the controller rod antennas vertically may have some effect in increasing range but will come at the expense of making the signal more directional. That can be a problem if the drone location becomes unknown for any reason. Most pilots arrange the two rod antennas at a 90-degree angle to each other to get the best general field of coverage.

"Yuneec states there is a redundant signal to increase transmission security. What kind of signal is meant, could this be explained without being to technical?"
The reference to "redundant" is likely the programmed swap of drone control from the 2.4GHz to the 5.8 GHz in event of failure of the 2.4Ghz.

 

[busx]

Thanks for your replies. I know these tech. specs and the fotos. About the photos I 'm in doubt: I do not know or understand what the function of the internal printed circuit-boards are (sorry, limited knowledge) but it seems as if the rod-antennacables go to different printed circuits? If so, different transmitting-functions for both rod-antennas?

The polarization and the way how to position the rod-antennas seems to be clear: should in fact be vertical, but to make sure you will have transmission independent of drone-position one antenna at 90 degrees might be a better choice? But is this really the case, or is each antenna sending and receiving on an different (2.4 GHz) frequency and/or transmitting a different function (RC and/or video)?

About the use of 2.4 and 5.8 GHz: yes, both are declared by Yuneec (as present), but this does not tell us about the function I think. In the manual (at CE, FCC, technically) they state: 2.4G, 2.4G Wifi, and 5G WiFi. The user-specs of the ST16E are very clear: transmission with the H520E is 2.4 GHz only.

As far as I know, partly by reading tech. sheets and partly by getting information from Yuneec Europe, things are as follows:

Opposite to the H520 (it's cameras have their own 5.8 GHz transmitters?) the H520E-cameras video-signal is connected to the OFDM-unit (which, they say, is only 2.4 GHz) and thereby also makes use of 2.4 GHz. According to Yuneec-EU the (circular polarized) 5.8 GHz wifi is only used for connection to the internet (downloading maps and updating) by using an internet WiFi-hotspot.
If the information from Yuneec-EU is right than they will, in case of a weak signal, not switch to 5.8 GHz (the OFDM-unit is not able to do 5.8) and besides that, I read 2.4 usually gives a longer transmitting range so switching to 5.8 might not help.

To be more or less sure I have tried to receive video-transmission by using a normally used video-receiving 5.8 GHz fpv-goggles: no chance, no video. This is, besides the Yuneec-EU info, another sign of the video transmitting on 2.4 GHz (only) together with RC. If this is right than the use of the usual 5.8 GHz receiving goggles is not possible, good to know... (I am using the ST16E HDMI 720p output for my goggles).

If anyone known more about this matter I would be pleased.
- For instance: are the 2 rods used for different bands (within the 2.4 GHZ), or possible one for RC and one for Video? (this might make a difference for the positioning of them, one at 90 degrees or definately both vertical?).
- And about the redundancy: Yes, you usually use redundancy within the (same) transmission signal used, and the amount of redundancy can vary according to your wishes. But Yuneec states: In addition, the H520E is equipped with a redundant control signal. Does this mean they are using a separate redundancy signal? Do they possibly mean that, in case of loss of transmision, other 2.4 Wifi-channels will be used? If so, is this than a 'switch-on' at the moment the original signal is getting to weak or is this redundant signal there all the time, waiting for being used ?
Or is it simply redundancy in the 'normal' 2.4 GHz RC/Video-signal?

No easy matters, these transmission-things, I think. But maybe good to know more about it? Or to many unnecessary questions?