Lost connection on 500 meters altitude.

[FoxhallGH]

Seems the trick is not to stand directly below the drone. That’s how I manage it... get about 20’ back.

That's right - it doesn't seem to take much to get out of the spot.

 

[chriscuk]

@FoxhallGH I've got to pipe up and say that I do agree with you on the cross polarization issue I'll just assume that the device isn't perfect and the losses in cross polarization are not infnite but my take on it is....

Both Vertical....
Drone = Vertical polarisation. Nice null in the radiation lobe beneath. (25dbi+ ish)
Controller = Vertical polarisation. Nice null in the radiation lobe above. (25dbi+ ish)

Controller Horizontal....
Drone = Vertical polarisation. Nice null in the radiation lobe beneath. (25dbi ish)
Controller = Horizontal polarisation. Some power is radiated to the drone, losses will occur but it's not as bad as being in its null.

As before the very easy fix is to fly out a few meters

 

[Deleted member 93449]

What bird are you flying? You'll get different results depending on the transmission system being used.

 

[Venomvip]

It's Mavic 2

What bird are you flying? You'll get different results depending on the transmission system being used.

 

[maverickRKJ]

Well, just to cool down most of the responders... I'm not in US.
And we do not have law regulations to drones as of yet...

My question was if its supposed to loose connection like that at that low distance from controller.

i brought my mavic pro 400 meters in northern BC Canada lol no cops for miles where i was and out of any air traffic area according to my B4UFLY app

 

[sar104]

i brought my mavic pro 400 meters in northern BC Canada lol no cops for miles where i was and out of any air traffic area according to my B4UFLY app

Sounds like a perfect justification to break the law.

 

[Deleted member 93449]

i brought my mavic pro 400 meters in northern BC Canada lol no cops for miles where i was and out of any air traffic area according to my B4UFLY app

BC Canada 4.8 pop/sq km

Suffolk County, NY (where I live) 632 pop/sq km

New York City 784 pop/sq km

BC sounds like a perfect place to fly when you're away from an airport.

 

[AECSpatial]

I find this app very handy when doing my risk analysis, pre flight planning
Elevation Finder

 

[JAW]

Where in Suffolk? We have a house in Sayville.

 

[CFWB]

If the drone is straight up... would any horizontal position of the flat side of the antennas to the ground work pointed up at the drone?

 

[FoxhallGH]

If the drone is straight up... would any horizontal position of the flat side of the antennas to the ground work pointed up at the drone?

It's not ideal ... Any antenna system uses 'polarisation' ... A radio wave consists of an electric component, and a magnetic component (that's why it's a.k.a. an Electromagnetic Wave), with the direction of the electrical current, being at 90 degrees to the magnetic component. When you transmit from a vertical antenna, the receiving antenna needs to be polarised identically to the transmitting antenna to get the best induced signal. In the real-world, this means that since the Mavic's antennae are vertical in its front legs - then you are going to get the best signal connection between controller and Mavic, if the antennae on the RC controller, are also vertical.

 

[CFWB]

It's not ideal ... Any antenna system uses 'polarisation' ... A radio wave consists of an electric component, and a magnetic component (that's why it's a.k.a. an Electromagnetic Wave), with the direction of the electrical current, being at 90 degrees to the magnetic component. When you transmit from a vertical antenna, the receiving antenna needs to be polarised identically to the transmitting antenna to get the best induced signal. In the real-world, this means that since the Mavic's antennae are vertical in its front legs - then you are going to get the best signal connection between controller and Mavic, if the antennae on the RC controller, are also vertical.

I understand now! Vertical to vertical antennas is not at all ideal and no doubt the worst case scenario. Offset even a little would be more beneficial. Flat side of controller antennas to the flat side of drone antennas ideal.

Thank you.

 

[dougiefresh27]

Isn't the legal altitude limit 400ft / 122 m and you want to go over 1000ft higher than that.

Agreed! I would love to fly 500m up but I stop before the 400' mark. Keep it legal people.

 

[DanMan32]

Actually vertical to vertical is ideal with respect to polarization. However you also have the concern of radiated path.

AC horizontally away from RC:
Best is RC antennas up. Max radiation towards AC and polarity matches (both vertical)
AC vertically above:
RC antennas up: Polarity matches but radiation in wrong direction
RC antennas out: Radiation at max towards AC, but polarity is mismatched, 90 degrees out of phase.

 

[FoxhallGH]

I understand now! Vertical to vertical antennas is not at all ideal and no doubt the worst case scenario. Offset even a little would be more beneficial. Flat side of controller antennas to the flat side of drone antennas ideal.

Thank you.

I don't know if you understood what I meant? There is nothing wrong with vertical to vertical antennae - and that is in fact, the ideal situation. The problem is that when the drone is directly overhead, it is in a position where [if the controller is held normally] the transmitting antenna is presenting the minimum amount of 'surface area' to the receiving antenna, and the receiving antenna is also presenting the minimum surface area to the transmitting antenna.
Although - DJI's manuals do show that when the drone has horizontal distance from you, you should have the controller's antennae vertical, and when it is directly overhead, you should have the controller held so that the antennae are horizontal ...


I've tried to find information, but there is very little to show if the antenna wires in the Mavic front arms form an active component along the whole length of the horizontal arm and the vertical leg, or if the antenna is only active in the vertical leg. The antenna wire is a co-axial cable with braided [earthed] shielding around an active core. The active length of the antenna consists of the wire that is left exposed after the external sheath and braid is cut away. That remaining [active] length of wire is carefully calculated and will be a portion of the wavelength of the frequency used for transmission by the controller. An antenna consisting of a length of wire like this is known as a 'dipole' - and must be a quarter, half or full-length portion of the wavelength of the frequency it transmits/receives.

The wavelength of 2.4GHz radio waves is 125 mm, and for 5GHz is 60mm ... The antennae on the RC controller are around 60mm long, and the landing legs on my Mavic Pro Platinum are also about the same length - so I'd assume that the active part of the dipole antenna in the front arm, was in the 'vertical' leg only. A 60mm antenna would form a full-wave dipole for 5 GHz, and a half-wave dipole for 2.4 GHz.

 

[Hayds]

It's Mavic 2

Turbowing 2.4ghz 1watt amplifier, got my mavic air from 1300ft to over 5000ft straight up

 

[Bekanne]

Tried to get my bird 500 m altitude exactly above me to get nice shot. First it lost connection at arround 200 meters. Second flight it was perfect at 500 m and then completely lost video and controls until it descended at 380.
Is that supposed to act like that? Istn control and video range supposed to be much higher that?
It was smart remote controller on latest firware and secondary usual remote connected.
I can post flight logs If that is helpful to someone can give more info on that.

The signal was likely lost by the angle of the antenna.
Ignoring the 400 feet allowance for recreational reasons is a common cause of fly always due to wind.