sudden drop/regain in signal?

[88lance]

Hey everyone. Still slightly new to the drone scene, have about 3 hours on the new MA2. Have a question about signal strength. My signal bars stay at 100% for around 2,000 feet out, and then around 2,200, I get a sudden drop to about 25% signal bars. I am facing the drone and have clear line of sight, just farmland. If I stop for a few seconds and wait, it suddenly recovers to 100%. There is no gradual drop or increase, it just changes from 100 to 25 and back. Pushing on towards 3,000 feet away, it will do it a few more times. As long as I stop and wait a second it will go back to 100% bars. I have not sent the drone out past 3,000 because I am not sure what is going on. I read a lot about people sending it out double that distance, but I am kind of afraid to, not knowing if it is going to suddenly drop to 0% at once and just stay there. (although return-home should save it, but still). Is this normal?

 

[Phantomrain.org]

Hey everyone. Still slightly new to the drone scene, have about 3 hours on the new MA2. Have a question about signal strength. My signal bars stay at 100% for around 2,000 feet out, and then around 2,200, I get a sudden drop to about 25% signal bars. I am facing the drone and have clear line of sight, just farmland. If I stop for a few seconds and wait, it suddenly recovers to 100%. There is no gradual drop or increase, it just changes from 100 to 25 and back. Pushing on towards 3,000 feet away, it will do it a few more times. As long as I stop and wait a second it will go back to 100% bars. I have not sent the drone out past 3,000 because I am not sure what is going on. I read a lot about people sending it out double that distance, but I am kind of afraid to, not knowing if it is going to suddenly drop to 0% at once and just stay there. (although return-home should save it, but still). Is this normal?

Couple things to note: Is your clear line of sight over any trees and what altitude are you flying at. ?

 

[88lance]

Couple things to note: Is your clear line of sight over any trees and what altitude are you flying at. ?

There are a few trees, but they are below the line of site since I am on a hill. I started out at around 250 feet altitude, and noticed it does it less when I go up to 375', but it does still continue to do it. Since it goes back to 100% after a few seconds, im wondering if the short 25% reading is actually even accurate?

 

[Phantomrain.org]

There are a few trees, but they are below the line of site since I am on a hill. I started out at around 250 feet altitude, and noticed it does it less when I go up to 375', but it does still continue to do it. Since it goes back to 100% after a few seconds, im wondering if the short 25% reading is actually even accurate?

Did you notice how many actual satellites you had ?

 

[88lance]

Did you notice how many actual satellites you had ?

Just went and looked at the bars thinking I may have been looking at the satellite bars instead, but it is in fact the RC bars. I normally have around 15 or 17 when I take off, but I havent looked to see if that number drops when the signal drops to 25%. I'll try to check that next time I send it out. I havent noticed the satellite icon turning orange during flight though, so it is probably still good. I will watch it next time though.

 

[boblui]

I can think of two reasons :

1) multipath fading - the radio signal is typically reflected by various objects in the environment including the ground before reaching the receiver. By chance the the radio signals going through some reflection paths are out of phase and cancel each others out causing a highly localized dip in radio signal strength. If the drone or the controller is moved away from the dip, the signal strength will be restored. From : Drone Wireless Video Transmission - Technologies, Challenges and Probable Solutions ! - Techplayon :


2) the channel being used is subject to interference and the system switches to a different channel / frequency band.

 

[DanMan32]

I vote #2, though #1 can trigger #2.

 

[88lance]

Interesting, that makes sense. I also watched a few range test videos on youtube last night, and noticed other peoples seems to do this as well, usually a little farther away though, but it could be the area I am in. Next time I get some free time and decent weather I think I will go ahead and just push it a couple more thousand feet to see what happens. I also found some Yagi extender antennas on amazon. Not sure how good they are, but for 10 dollars, I havent lost much if they are trash. ?

 

[JackL]

You must have a cell tower or some other source of interference around. At 12,000 ft distance I have full signal and perfect video over the ocean. Try flying a different direction. You should be able to make 20,000ft+ from a hill with the stock rig.

 

[88lance]

You must have a cell tower or some other source of interference around. At 12,000 ft distance I have full signal and perfect video over the ocean. Try flying a different direction. You should be able to make 20,000ft+ from a hill with the stock rig.

That may be the issue then, 20K is a lot more than what I can do. I bought the Yagi antennas, and it definitely helped. I reached 6,000 feet before the first signal drop. It recovered until 7,000, when it suddenly dropped to about 10% and refused to recover. I flew in a circle to the side at 7K feet out for a bit to see if it would recover, but it stayed 10-20%. The only issue with this test, was going either left or right to make the circle put it over some hilly terrain that also had a lot of trees, although never behind any hills. So even if I was escaping a some interference by moving left or right, I probably was not doing it any favors by switching to rough terrain. I do have a lot of cell phone towers around the area, although they are a couple miles away, they may be cutting in a bit. I may try some more remote locations someday. For my travels and videos, I highly doubt I will need 7,000 feet anyway, but it is nice to know what it is capable of ? I am heading to a different location for christmas, I'll scope it out and see if it is good for another test run just for the heck of it, might get better results