Strange issue involving disconnect

[ivanatora]

Hey, guys,

I've just had a weird experience last night. Tried an altitude test on 500 meters - now I know people will start bashing, but every precaution were taken (uninhabited region, open field far away from restricted zones, shelter for me).

So, at one time drone stopped responding to sticks and I see 0 bars of signal strength on the remote. In the same time video feed is going strong. RTH button was working and the drone responded to it. At some time during descent the remote regained control and things went fine.

I have two questions here.
1. How can sticks loose control, while video feed is going? If there is RF link issue, shouldn't it affect everything in between you and the aircraft? Are video and controls two separate connections? The RTH button was working - is this operation not sent trough the same "stick controls" connection?

2. Why did remote lose signal strength? 500 meters with no obstacles is far within it specs, I think? Is vertical distance limit not the same as horizontal distance?

Thanks in advance.

 

[OzoneVibe]

Re (1) ... possibly ....
Your RC transmission isn't equally strong in all directions ... it has it's "sweet spot" that has to be correctly orientated to the MP for optimum connection.
Your MP transmits the Video in all directions beneath the drone.
So - two different communications that do not necessarily have to coexist and are not mutually dependant.
Re (2) ... dunno.

 

[ivanatora]

This image about the controller antennas position might be answering my (2) https://mavicpilots.com/attachments/rc-optimal-transmission-jpeg.25619/

 

[Bunny Too]

Hey, guys,

I've just had a weird experience last night. Tried an altitude test on 500 meters - now I know people will start bashing, but every precaution were taken (uninhabited region, open field far away from restricted zones, shelter for me).

So, at one time drone stopped responding to sticks and I see 0 bars of signal strength on the remote. In the same time video feed is going strong. RTH button was working and the drone responded to it. At some time during descent the remote regained control and things went fine.

I have two questions here.
1. How can sticks loose control, while video feed is going? If there is RF link issue, shouldn't it affect everything in between you and the aircraft? Are video and controls two separate connections? The RTH button was working - is this operation not sent trough the same "stick controls" connection?

2. Why did remote lose signal strength? 500 meters with no obstacles is far within it specs, I think? Is vertical distance limit not the same as horizontal distance?

Thanks in advance.

Did you change the orientation of your antennae? If you were flying (almost straight) up you would have had to make several adjustments to your antenna throughout the flight. Toward the end of your flight your antenna would need to be parallel to the ground.

 

[ivanatora]

No, I did not. I suppose this was the issue here.

 

[Bunny Too]

No, I did not. I suppose this was the issue here.

Do not know if it is the answer but something to try next time.

 

[locoman]

Also, I think the antenna in the MP are in the front legs, so if you were straight up, the antenna legs are pointing straight down, probably not best orientation for tx/rx

 

[ivanatora]

Yeah... Checked the emission diagram for the rubber duck antenna - http://www.hsdivers.com/Ham/images/M9-2.png it looks like it is very weak above and below the axis. I would say one of the disconnect mysteries is solved. But why would the video feed not suffer from this, too?

 

[Bunny Too]

Yeah... Checked the emission diagram for the rubber duck antenna - http://www.hsdivers.com/Ham/images/M9-2.png it looks like it is very weak above and below the axis. I would say one of the disconnect mysteries is solved. But why would the video feed not suffer from this, too?

Video feed is on a different frequency band, perhaps it is more tolerant of week reception?