Power Cables

[RatHat]

Ok, I keep seeing people referencing power cables as a possible reason for fly aways. I have flown close to power lines without problem, but I tend to steer clear of them as much as possible now. This limits take off points for me quite a lot. Living in Indonesia, all power lines are above ground, and are strung along the roads, so when driving around trying to find nice areas to fly and video, I am often put off by the amount of lines close to where I would have to take off.

And what about radio masts? Indonesia has an abundance of radio masts used for the cellular network. Do these affect multi rotors?

Can anyone advise just how much influence above ground power lines really do affect a quad, particularly using the DJI compass? Also are there compasses around that can replace the DJI ones without being affected by power lines?

 

[gtranquilla]

I have over 25 years electrical engineering experience in industrial power including several years working for electrical utilities. Also I have a HAM radio license which provides a lot of valuable insight on this topic. Once you get within 2 feet of a powerline you will most likely lose control of your MR. Beyond that for a few feet you may still have adverse affects on your digital compass but not on your GPS incoming data. Be more cautious with radio masts depending on their transmit frequencies and even more cautious anywhere near microwave towers and radar. Even fhss 2.4Ghz signals can get overwhelmed by emi - electromagnetic interference when MR gets too close. High energy RFI - from radar and microwave can even kill insects and drive away small birds and/or cause blindness at extremely close range. Overhead powerlines used to be much cleaner but now that electrical clients use a lot of ASDs, VFDs there is now a lot of emi reflected back in to the grid from the client's end. It's all about the inverse square law of point source radio transmission.

Ok, I keep seeing people referencing power cables as a possible reason for fly aways. I have flown close to power lines without problem, but I tend to steer clear of them as much as possible now. This limits take off points for me quite a lot. Living in Indonesia, all power lines are above ground, and are strung along the roads, so when driving around trying to find nice areas to fly and video, I am often put off by the amount of lines close to where I would have to take off.

And what about radio masts? Indonesia has an abundance of radio masts used for the cellular network. Do these affect multi rotors?

Can anyone advise just how much influence above ground power lines really do affect a quad, particularly using the DJI compass? Also are there compasses around that can replace the DJI ones without being affected by power lines?

 

[RatHat]

Thanks for a great answer!

So, as a rule of thumb, you should stay at least 10ft away from normal overheads? Would that be about right?

This has certainly made things clearer for me, and I thank you for taking the time to respond.

 

[Scott Drysdale]

Yes..... By the way..... makes no difference which compass one uses..... they all respond to the earth's very weak magnetic field until there is another magnetic field that is closer. Wherever there is a wire or conductor with electricity passing through it, there will be a corresponding magnetic field. While a straight wire will have an extremely weak magnetic field, coiled wire will have a much stronger magnetic field, e.g., electromagnets and electric motors.

Thanks for a great answer!

So, as a rule of thumb, you should stay at least 10ft away from normal overheads? Would that be about right?

This has certainly made things clearer for me, and I thank you for taking the time to respond.