Just curious what the phantom is using to achieve 4 mile range, when my bugs 3 only goes 300 meters or so?
eli5 maybe :P or even direct me to places where I can do some more reading? thanks
Posted Mar 21, 2018, 4:41 PM UTC
[deleted]
Thanks
The main differences are the frequency of the radios, and the power able to be supplied to the radios.
MJX Bugs 3 radio uses conventional AAA batteries and the DJI P4 radio uses Lithium Polymer batteries. Less power to the antenna means less effective range - usually.
Now on to the frequency. Due to the MJX being a FPV style drone, using 5.8 GHz is good for two things. Data tranmission speeds can be quick, and latency (or input delay from radio to drone) can be lower. These are arguably the most crucial things in FPV flying.
5.8Ghz that the MJX uses is a higher energy wave and runs out quicker and is subject to a lot of obstructions from natural objects. 2.4GHz that DJI use are a lower energy wave, broadcast further, and penetrate objects better.
Couple the better signal with the higher power transmitter, and you get increased range.
The battery power thing is bullshit. You get multiple miles with a very low transmitter power consumption. The taranis qx7 has something around 160ma at 9v, (6 AA in a series). That's almost nothing. You're never gonna reach a transmitting power consumption that is too high for AA batteries with any realistic setup (especially if you want to fly legally).
All that matters is receiver/ receiver antennas, transmitting power (100mW for the taranis qx7) / transmitter antenna and the frequency of transmission. Antenna = bad mounting or bad antennas (dbi values)
Lower frequency means bigger antennas hence we stick to 2,4ghz (standard, used by frsky, dji and many more), 5,8ghz (usually used for video transmission, dji also offers rc control at this range) or 900mhz (tbs).
Please don't spread misinformation.
Transmitter power is one of the main factors in determining radio signal range. Plain and simple.
We stick to 2.4 GHz range because it’s ‘free’ to broadcast, doesn’t require licensure to use, and less prone to interference.
Not spreading false information. The guy wanted an ELI5...
The p4p uses a different communication architecture called light bridge that is more resistant to interference that can plague WiFi. The phantom 3 standard or 4K use WiFi which means it is susceptible to interference to other WiFi. It has to do with the way the data is transmitted and read which allows the light bridge drones to have more range. That’s the mist basic way to explain it without going into things like frequency hopping schemes and other digital comm protocols.
The ELI5 answer is, better technology. You're comparing an $80 drone to a $1500 drone (for a P4Pro). It's kind of like asking why a Ford Fiesta can't do 200mph, but a Ferrari can.
i already know it's better and more expensive. Is it still 5.8ghz? it's definitely not wifi. (is it?) do they somehow use the gps to control the drone? If so why is there range at all?
how about eli7 or 8 ?
In addition to this, keep in mind that if that is being published by dji, it's likely under perfect conditions. Flat, no hills, no tall buildings, no obstructions, etc. Further, you are supposed to maintain line of sight (please correct me if i'm wrong), which you can't do at that distance.
Line of sight does not mean you actually have to be able to see it, just that you have a clear line to it with no obstructions in the way.
I believe the "line of sight" he's referring to is the rule in the U.S. that says you have to be able to see the drone with the unaided (except for corrective lenses/glasses) eye. And I think you are referring to "line of sight" as it relates to radio transmissions.
Technically the same, because you have to prove that i cant see it. If i have a clear line of sight, who is to say i cannot see my drone at 2 miles out?
real eli5:
Both your remote and your drone have ears and a mouth (antennas).
You make the remote scream by moving the sticks, or pushing the buttons. The drone will listen to this. The drone screams back the video and other data which the ears on your remote will listen too. (some drones have only ears and don't send any video or data back)
If your remote can scream harder, the drone can hear you further away. (same for the drone screaming back). The government tells us how hard we are allowed to scream. This is actually a whisper compared to the available power in a battery (AA batteries are cheap, a rechargeable LiPo is expensive but convenient).
But screaming hard is not the only thing that determines how far away the drone can hear you. If your drones ears suck you cant hear much when you go further away. Also if you scream in the wrong direction you will not be heard either. A cheap drone has a cheap mouth and cheap ears. It might scream at the legal limit, but is much less efficient and therefore less effective. An expensive drone will have more efficient (better quality) ears and mouth.
Besides the quality of the ears and mouth (antennas) we can scream in different languages (frequencies). Again the government tells us what languages we can use with a drone. (we don't want our screaming to mess up the local radio station or police communication) If a lot of people scream in the same language it is difficult to hear what everyone is saying (interference) expensive drones learn multiple languages so they can switch to one that is not used much in the area.
GPS works different. there are a bunch of GPS satellites flying around the Earth they only have a mouth. Your drone only has a GPS ear (GPS receiver) The GPS satellites all scream their name and location at the Earth. Your drone is listening to the GPS satellites screaming and based on which satellites it can hear and how good it can hear them, the drone can calculate where it is. If the drone has a mouth the drone can then then also tell the remote where the drone is. The GPS satellites have no idea where anything is. They are just screaming but have no ears.
edit: spelling